My very first match up is between:
The Pitbull: http://images3.wikia.nocookie.net/__cb20070413132420/cnc/images/archive/9/9e/20070831095418!Pitbull.jpg
and the Rocket Warthog: http://halo.wikia.com/wiki/M12A1_Light_Anti-Armor_Vehicle
Which is the superior vehicle? Which one would win in a fight.
Now, I will admit to being somewhat of a Halo fanboy. But, honestly, if I had to pick a winner now, I'd choose the pitbull. Well, debate people.