Oklahoma City has never been a particularly attractive free-agent destination, so it wasn't too easy to conjure up a list of the Thunder franchise's best signings since 2008. The Thunder also notoriously found it difficult to keep the best free agent in their history, failing to come to terms with a new contract with Kevin Durant in 2016.

Nevertheless, in terms of marginal moves, there have been a few across the past 15 years that have made a positive impact on the franchise. Here are 10 of the Thunder's best free agent signings.

(Note: players acquired by the team via trade who decided to re-sign with the team aren't considered for inclusion on this list. If they were, Paul George would top this list — and it isn't even particularly close. Russell Westbrook, for his career, didn't reach free agency until 2023.)

10. Markieff Morris

Speaking of reinforcements from the buyout market, the Thunder, in need of more depth and spacing (yet again) with the intention of mounting a deep playoff run in mind, picked up Markieff Morris in February 2019. Morris was solid for the Washington Wizards before he received his buyout, giving the Thunder high hopes as he could have functioned as a small-ball option for them at the five.

However, Morris failed to bring the impact many thought he would in a Thunder uniform. He was uninvolved in the offense, and he wasn't exactly a stifling presence on the defensive end. His OKC stint ended on a whimper, as he struggled mightily during the team's five-game series meltdown against the Portland Trail Blazers — the series where Damian Lillard bid the team adieu with a bomb from halfcourt.

9. Caron Butler

When the Thunder picked up Caron Butler off the buyout market, he was so far removed from his days as a top-notch impact player. Nevertheless, Butler was still helpful for a team that found it difficult in the early 2010s to build some impressive depth behind Kevin Durant and Russell Westbrook.

Providing the team with some much-needed spacing and veteran knowhow, Butler played a firm role during the Thunder's playoff run in 2014. He played in 18 of the team's 19 playoff games, averaging 23.3 minutes. He wasn't very efficient from the field, but he provided the team with some outside shooting (35.6 percent from deep on 3.3 attempts per night during that postseason run). In terms of helpfulness, Butler certainly did his job for the franchise even though his stint didn't last very long.

8. Anthony Morrow

Anthony Morrow is not the most upstanding citizen, that much is clear. Nearly six months ago, he was charged with assault by strangulation, second-degree kidnapping and communicating threats, and he only got out of prison after posting a $15,000 bail. That is not the behavior we tend to associate with players who get the privilege of inclusion on these kinds of lists.

But at least for one moment, no matter how daft it is, we will be evaluating the art (his contributions on the court) apart from the artist. And Morrow, before he found himself in legal hot water, had his fair share of good moments in a Thunder uniform, especially during his first year with the team in 2014-15.

He was a reliable source of floor spacing, making 255 threes during his two and a half year stint in Oklahoma City. He was also one of the Thunder's rare players during this era of basketball who could shoot on the move, come off pindowns and curls and knock down shots from deep.

It's just too bad that Morrow's post-NBA life has gone to complete and utter crap.

7. Patrick Patterson

With the Thunder looking to crash the upper echelon of contending teams in 2017 following their blockbuster moves for Paul George and Carmelo Anthony, two All-NBA forwards, they added Patrick Patterson in free agency, a solid role player who impressed with the Toronto Raptors for the previous four seasons.

Patterson was a reliable defender capable of multiple kinds of pick-and-roll coverages, and he was also a fairly reliable floor-spacer. It made him an important bench piece for the Thunder, although that isn't saying much given the team's lackluster depth behind its starting five.

However, in two seasons with the Thunder, Patrick Patterson didn't exactly impress. He averaged just 3.8 points on 36.4 percent shooting from deep across 151 games with the team, regular season and playoffs combined.

6. Corey Brewer

The Thunder had some growing pains during the 2017-18 season while integrating Paul George and Carmelo Anthony into the lineup. But in January 2018, OKC seemed to have found its groove, stringing together a few wins while cementing their status as one of the best teams in the Western Conference. But then Andre Roberson ruptured his patellar tendon, creating a gaping hole for the team at the two-guard position.

That's when Corey Brewer entered the fray. Having coached him back in Florida, Billy Donovan loved to have Brewer on board, and to his credit, the 6'9 forward helped immensely. He became the Thunder's starting shooting guard to end that season, scoring in double digits in 11 of his 18 regular season games for OKC.

Alas, he wasn't able to provide much impact for the Thunder in the postseason, as OKC rolled with the five-man unit of Russell Westbrook, George, Alex Abrines, Steven Adams, and Jerami Grant when it mattered most.

5. Raymond Felton

Raymond Felton was another of the Thunder's low-cost additions in free agency, a pitfall of the team's focus on paying their starters each a contract of upwards of eight-digits per year. But at the very least, Felton was an improvement over the Thunder's former backup point guard to Russell Westbrook; going from Semaj Christon to Felton must have brought then-head coach Billy Donovan some relief.

Felton was a solid enough backup for Westbrook, and he even played some crunch time minutes for the team when the Thunder opted to go smaller. Felton was a much more reliable shooter than Christon, and he was a pull-up threat, helping him better set the table for his teammates. However, one of the lasting memories of Felton in a Thunder uniform was his involvement for the team when they couldn't buy a bucket to save their lives in Game 6 of their first-round clash against the Utah Jazz five years ago.

In 115 games with the Thunder, Felton averaged 6.1 points and 2.2 assists — not too shabby of a return for someone the team picked up for the veteran minimum.

4. Derek Fisher

Yet another pickup off the buyout market, this just goes to show that the Thunder didn't exactly prioritize adding depth via free agency in their roster-building plans. They merely settled for picking up other team's scraps in the middle of the season, with Derek Fisher being one of those midseason additions thrown in the fire of a push for a championship.

The idea behind adding Fisher for the playoff push isn't a bad one on paper. After all, Fisher was part of five championship winning iterations of the Los Angeles Lakers, and he's never afraid to take big shots under the brightest of lights. However, he was pushing 40 when the Thunder acquired him, so he wasn't exactly a consistent player on either end of the floor anymore.

Nevertheless, Derek Fisher was still a helpful presence, someone former head coach Scott Brooks trusted in crunch time and someone who acted as a composed presence in the locker room. And for the low, low cost with which they added D-Fish, that's about as good as it gets.

3. Mike Muscala

The 2019 offseason was a trying one for the Thunder. Reeling off Damian Lillard's insane halfcourt bomb that ended their season, the Thunder made a decision to start from scratch and blow it all up. Nevertheless, Sam Presti coveted Mike Muscala's services and pursued him heavily, believing that he could help out the team in whatever situation they find themselves in.

That is exactly what Muscala did. He served as a solid backup for the team in three and a half seasons, spacing the floor reliably. In 168 games with the Thunder, he averaged 7.0 points and 3.0 rebounds a night on 39.2 percent shooting from deep, while surviving just enough on the defensive end of the court.

2. Nerlens Noel

Thunder fans were crying out for a legitimate backup in 2018, as OKC foolishly relied on the inexperienced Dakari Johnson to serve as Steven Adams' understudy the previous season. Patrick Patterson, for better or for worse, failed to establish himself as someone Billy Donovan trusted as a small-ball five. Thus, the clamor from Thunder fans was understandable.

So when the Thunder added Nerlens Noel for cheap in 2018, there was celebration. Adams finally had a reliable backup in Noel — a plus defender with quick hands that disrupted passing lanes and incredible leaping ability combined with impeccable shot-blocking timing.

Noel formed fun connections with Dennis Schroder and Russell Westbrook, and he was a refreshing change of pace for OKC as someone who can blitz the pick-and-roll more effectively than Adams did. Alas, the Thunder's 2019 season ended in tears still, as Noel and company struggled to hold Damian Lillard in check.

1. Isaiah Joe

It's interesting to see that the best free-agent signing the Thunder made in its history came just last season, when they picked Isaiah Joe off waivers from the Philadelphia 76ers.

It's fair to ask whether Joe's placement as the top signing on this list came as a result of recency bias. But it's difficult to argue that given how well he has played for the Thunder thus far. He has become one of the most elite marksmen in the league, shooting over 40 percent from deep on 5.4 attempts per game. Every team needs its designated sniper, and for the Thunder to have plucked theirs off of waivers and for them to have his contract under team control for two more seasons? That is simply incredible business.