I have both games.  I have noticed they are very similar in game play style...  Below is a comparison of some of the features.

If you liked Crackdown you will probably enjoy Mercenaries 2...  An interesting note though...  Mercenaries 2 is sitting at 74.7% on gamerankings.com... Crackdown is 83.6%...  I really see Mercenaries 2 as being much larger (More missions and destructable fun) and deeper gameplay overall... 

Crackdown has Co-Op...Just like Mercs 2. Dang it, I wish BOTH games had offline co-op.

I've only played 3hrs of Mercs 2 (and may not get much more time on it), but it's very fun. It's more akin to Just Cause without the crazy glitches.

Crackdown was awesome, but I haven't played Mercs 2 so I cannot compare.

Just Cause + Crackdown = Mercenaries 2

All are fun!

You forgot Peter Stormare. Crackdown, No. Mercenaries 2, Yes!

For me Crackdown wins this competition by far although Mercenaries is of course a good game.

First I have both games and I can tell you why crackdown scored higher. The game is more polished. Mercs 2 is by EA one of my least favorite publishers. They always seem to release games with TONS of potential but fall short Mercs 2 and Army of Two come to mind.

Both had enormous potential but EA seems to release games that are just missing that one extra, and the polish.

Crackdown was polished no bugs and fun I agree with the higher rating. Mercs 2 had the potential of being a better game but EA rushed it out the door.

You mention things like grow entourage, capture people and gain favor with factions. Growing the entourage was ok but really just an extra mission not sure added much. Capture people so what half the time they got killed anyways no added fun and Factions is pain in the A@# I had to bribe them so they would pick up an HVT I captured for them cause I got them mad. That was a minus in my eyes.

I agree Mercs is a fun game though

You say that because you haven´t played the game longer. Wait until you ask your pilot to bring you stuff and pick up resources.

what glitches mind telling me ive beat the game twice now, and am on the billionaries list #498 (though i have moved back was originaly 480 damn people connecting late)

the worst three things i have seen were the servers the first two days, once i blew my self through the map and could not get out of the water was under the island, and getting traped in a sinking ship in co-op... thoughs massive up landing craft that sucked.

out side of that nada, im on my thrid run through to get the last achivment get all hvts alive, and just like in the prior game its a pain

on crackdown geat game cant wait for them to get cracking on number 2 as soon as apb is done