My top 5:

Michael Cooper

5x Champion, 8x All-Defensive, 1x DPOY. He was the defensive stopper of the Showtime Lakers and a key part of their championship dynasty. He came off the bench mostly however, and never got the chance to be an All-Star

Rod Strickland

In Strickland’s prime, he was one of the best ball handlers in the league, extremely difficult to stop on the drive, and most incredibly, made an All-NBA team despite never being an All-Star. Why he was never voted in is a mystery, as he was averaged solid numbers of 16/4/8 during his prime.

Cedric Maxwell

The only Finals MVP never to be an All-Star, Cedric Maxwell played an important role as SF for the Celtics while Bird played PF for them, during the early years when Kevin McHale came off the bench. In his prime he was good for 17/9/2 a game. I think he should have been an All-Star at least once. Not sure why Cornbread never made it in, perhaps he was overshadowed by Bird and McHale?

Lamar Odom

One of the most underrated players of all time. Odom was a key part of the late 2000s Lakers teams. Part of the reason both him and Gasol get underrated is because of the numerous Kobe fans out there. Kobe fans rarely talk about Gasol and Odom and instead of focus on guys like Smush and Kwame instead because they want to push the narrative that Kobe carried his team without any help and won 2 rings by himself. It’s just not true. Gasol is another story (and should have been on the NBA 75th team), but Odom was a very talented big who could post you up, shoot, rebound like a center but also pass like a guard. He was averaging 16/10/5 as a starter before he became a very solid 6th man.