hopkins is the most clever fighter i have ever seen. he can change styles back and forth between a fight, fights so effectively dirty, utalizes the ring and his outside ring remarks and actions are offensive and shameless to the point that he makes his opponent blind with rage when they fight him.
roy doesn't get mentioned enough. other than that i agree with floyd, srl, hopkins etc.. also, i would add barrera.
SRL, Sweet pea, Ali, Mayweather jnr, Hopkins. But if we also take into account stuff behind the scenes and staying in shape, my pick would be Mayweather jnr, quit when there was little to gain and risk was too high, never out of shape, became popular changing his public image from "good" to "bad" and making profit out of it...oc theres a chance we might see him again tho.
It's basically the more defensively minded fighters who have to use their smarts more. Mayweather, Hopkins, Winky, Sweet Pea - while maybe not the cleverest of the last 50 years they are still extremely clever fighters. Techincal fighters aswell like Ricardo Lopez.
somehow he managed to beat morales 2 times out of 3 (while to me he won 1 and 3), and especially in the third he showed that it was him who seemed to have understood morales better than vice versa. i think, morales may even be a better boxer or puncher overall (and they got equal heart), but in the end it was barrera who managed coming out on top because he got himself under control better. also, how he handled naz was an even better example of him executing a plan completely.
Okay, I mentioned Pernell before, I'm going to do a more complete list, in no particular order. (Note: I'm only naming guys I have seen, so if I haven't seen them fight I'm not giving it to them for reputation alone). Archie Moore. (Started before the 50s, but boxed through them and into the 60s). Pernell Whitaker. Willie Pep. (Ditto what I said for Archie). Muhammad Ali. Ray Leonard. Bernard Hopkins. Floyd Mayweather. Nicolino Loche. Roy Jones.