I purely loathed EA when they started ruining sports games a while back, especially with the entire 2K Sports debacle.
"Hey! They're selling a better game at 1/3 the price! Better buyout the NFLPA so we can go back to charging $60 for roster updates!"
After that sting wore off (read: I quit playing sports games), I can now at least respect EA for playing it smart and buying up talented devs like Bioware and DICE and giving them lots of money to make good games. Sure, they still do shitty things (like the whole micro-transaction fad and charging for stat-boosts), but they've at least made steps in the right direction to improve games.
Activision on the other hand is just as greedy if not more so, but they (read: Kotick) actively run good games into the ground while bragging how they want to charge more money for less content. They shit on their own development companies (Infinity Ward, Red Octane, etc.) and I really can't for the life of me imagine what Bungie was thinking signing on with them. Unless of course it was simply "$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$!!!!!!"
As much as both suck, look at their track records. EA games at least tend to get better with each iteration (Madden, NHL, Sims, etc. are better than ever), while Activision's only get worse (Guitar Hero, Tony Hawk, Call of Duty, etc.).