well if were merely basing our favourite vehicle off looks of PS2 then I'll even go with the Vanguard, it looks like a proper tank.
The new variant of the prowler has some nice features but over all it doesn't impress me at all as a tank design, has more of a parade float feel and it's off centre cannons... well I like symmetry and they make me nauseous to the bottom of my gut.
If I had my way I'd tear down the design and put a curved TR version of the RL Merkava tank in its stead.
A close second favourite of mine is the new Lightning, it's a lil beast