depends on if you are just listing the best 5 at each position, or if you are building a team.
Best 5 by position:
PG - Magic
SG - Jordan
SF - Bird
PF - Duncan
C - Shaq
If I was building a team though... this would be my lineup...
PG - Nash
SG - Jordan
SF - Pippen
PF - Duncan
C - Hakeem
My reasoning for that team... Jordan and Duncan are obvious shoe-ins.
Nash gives you everything you could want offensively in a PG... shooting, passing, vision, penetration. The shooting is probably what I like most out of him. Greatest shooter in NBA history IMO. And can you imagine the open shots he will get with guys like Duncan and Jordan, as well as the easy buckets he can find for those guys? He can average 20 ppg on wide open 3's ALONE.
Pippen gives you a versatile lockdown defender, who doesn't need the ball to be effective, but can also score points when needed to, and is very athletic, leading to easy scores, especially with someone like Nash running the point.
Hakeem is probably the most versatile C ever, and can do anything you want a center to do. And with him and Duncan manning the middle, then it doesn't really matter how poor of a defender Nash is, as long as Nash doesn't leave anyone open for jumpers (which shouldn't be a problem since if someone gets by him, Duncan and Hakeem will give them a warm greeting)