

Lasts a good 8-16 hours to beat the campaign the first time, and there's a ton of unlockables (costumes, weapons, a new difficulty), on-top of Mercenaries Mode, which is easy to sink onto. Resident Evil 5 is a bit more all-around solid, not really a horror game but quite a fun arcade-shooter with a pretty competent campaign.

As I'm sure will be suggested a few times, but Resident Evil 5 & 6.
