Maximum cooling (Cheapest = 1, Most expensive = 4)
Titan Fenrir (2)
TRUE 120 with a decent fan (4)
Scythe Mugen II (1)
Noctua NH-12p (3)
Quietest
All AM2/2+/3 coolers are compatible with each other - the socket is virtually identical.
If you want great cooling cheap, get the titan, if you want cheap and quiet, get the Scythe.
If you want the best cooling for the volume level, get the Noctua. If you want the best cooling you can get without the racket the Titan makes, get the TRUE (the titan is loud)