[quote name='shippo' post='1252614' date='Jun 1 2011, 12:58 PM']Improved slap sound, fuzz, synth, filter, compression and some different amp sounds[/quote]
I'd probably say a Line 6 Pod HD if you're after Amp Emulation. If it's just effects then there are loads to choose from but the Amp Sim stuff is where it starts to get a bit more complicated. My advice though would be a Line 6 M9 and use EQ and Drive to simulate different amps though.
Dan