The Seattle Supersonics are probably the best team in the game. They have three players who can all drain the 3 pointer: Rashard Lewis, Ray Allen, and Luke Ridnour. It is possible to take about 45 to 50 threes on average per game with them. Note: Ignore the bad rating on the main menu.
The easiest way to have a successful season is to play as the Rockets and trade a player under 70 overall for Gilbert Arenas. Then, trade a player under 80 overall for Kobe Bryant or Dwyane Wade. Next, go into your line up and make sure it is as follows:
Yao Ming (C) Mutumbo (PF) Tracy McGrady (SF) Kobe Bryant or Dwyane Wade (SG) Gilbert Arenas (PG).
This creates an excellent rebounding team with the double center setup, as well as a great three pointer team with Bryant or Wade and Arenas. It also sets up a good driving team with Bryant or Wade, Arenas and McGrady.
Select the Phoenix Suns as they have Nash, Bell, and Barbosa, which have a 89 3 Point rating, making possible to make plenty of three pointers with them.