I wish they will keep the classic teams we have now in 2k12 for 2k13 and just add some new ones. But if they limit it to 34, then here's my list for NBA 2K13:
1964-65 Celtics (Russell)
1966-67 76ers (Wilt)
1969-70 Knicks (Reed/Frazier)
1970-71 Bucks (Kareem/Oscar)
1971-72 Lakers (West/Wilt)
1974-75 Warriors (Rick Barry)
1976-77 Blazers (Walton)
1976-77 76ers (Erving)
1976-77 Jazz (Maravich)
1982-83 Sixers (Moses/Erving)
1985-86 Celtics (Bird)
1985-86 Hawks (Nique/Spud)
1986-87 Lakers (Showtime)
1988-89 Pistons (Bad Boys)
1987-88 Bulls (Air Jordan at his best)
1989-90 Trail Blazers (Drexler)
1990-91 Warriors (Run-TMC)
1992-93 Suns (Barkley/KJ/Majerle) BARKLEY AGREES
1992-93 Hornets (LJ/Zo/Muggsy)
1992-93 Knicks (Ewing/Starks)
1993-94 Warriors (Sprewell)
1993-94 Rockets (Hakeem)
1993-94 Bulls (Pippen)
1994-95 Magic (Shaq/Penny)
1995-96 Bulls (MJ/Pip,Worm)
1995-96 Sonics (Payton/Kemp)
1996-97 Jazz (Malone/Stockton) = This is younger than the 1998 batch in 2k12
1996-97 Hawks (Mutombo)
1997-98 Pacers (Reggie) REGGIE ALSO AGREED
1999-00 Lakers (MVP Shaq/Frobe)
1999-00 Raptors (Vince/T-Mac)
2000-01 Kings (C-Webb/J-Will) = Replaced Bibby
2000-01 76ers (AI) IVERSON DESERVES TO BE BACK
2002-03 Spurs (Duncan/Robinson)
Additional 6 to make it all to 40 teams:
1997 Pistons = Grant Hill
2003 Nets = Kidd/Martin
2004 Pistons = Bad Boys II
2004 T'wolves = Best T'wolves team to date
2005 Rockets = Yao/T-Mac
2005 Suns = Nash/Amar'e/Marion/Joe Johnson/Q-Rich