Halo by a mile.
If Gears 2 didn't have horde it would have been a 6 hour long game experience and an average one at that. Gears tends to be way too scripted with the vehicle sections, QTE and linear shooting.
Halo on the other hand gives you the freedom to use the terain and surroundings and figure out how to beat the bad guys. ITs much more engaging to run for your life when a hammer wielding brute is chasing you than to just dig in for cover and shoot a guys down in Gears.
And this is before the multiplayer starts which halo rapes almost any game in with coop and online deathmatch.
@Kasz216 - if you liked Horde mode, Firefight in ODST should be something you will enjoy as its ebtter than horde in every way. But horde was here first so it gets a point for that...







