Most people ,myself included, have Iverson ranked higher than Nash, myself only slightly (#42 and #47 IMO), in terms of the Greatest players ever list. But I would rather have Nash instead of Iverson. Nash is a team first player capable of running an efficient offense that can overcome most obstacles, shown by his multiple deep playoff runs with various teams, his 2006 run with 2/5 starters injured shows that. But his willingness to run a team first offense and not gun at times also hindered him. That one playoff run in '05 when he let it fly was incredible, he put up 24/11 on 52/39/92 in 15 games. Imagine if he was gunning like Iverson, I have no doubt in my mind he would put up around 25/8. He also ran the #1 offense for 8 years straight, with different coaches,systems and players.
But let's be real here, neither could really play defense, because they weren't big enough. We all respect and revere Iverson, but I ain't taking him over Kobe, Nash, and Ray Allen if I'm trying to win.
Iverson needs a specific team around him, other scorers don't fit well with him. That's why his deepest runs were with scrappers and defenders. When he was with Melo, one of the greatest scorers ever, he had 2 consecutive 1st round exits. He's played with a lot of different types of players, including, but not limited to, future 30 PPG scorer Jerry Stackhouse, 2 players who won Defensive Player of The Years while they were actively on his team (Mutombo in '01 and Marcus Camby in '07), Andre Iguodala and Kyle Korver simultaneously, C Webb (a bit unfair, but he was still dropping 20/10 with Iverson), that's just to name a few. He's a very hard player to build around. He's very rigid in who he is as a player. He's also, to be fair, probably one of the cheapest players to build around, since you can find defenders and scrappers almost anywhere. He even had a young Bowen on his team for just slightly above the minimum, then almost immediately he shows he's one of the best defenders on the planet after he leaves Philliy and gets traded to Miami, then makes the All-Defensive 2nd team.
The one time he did make the Finals, it was because Stern rigged the Bucks vs 76ers so the more marketable match-up of Kobe vs Iverson would happen. Maybe it was just the fact that the East was weak and some team from the East had to go to the Finals. I do hold him playing in the East and not getting deeper runs more often against him, like I do Tracy McGrady. The East at that time was probably the weakest conference in the history of the NBA, up until about '04. So I don't hold a lot of the East stars runs in as high a regard as others if they haven't succeeded in the West, prior to or after their East runs.