Gears Of War is Halo for those with style and who don't fear looking death straight in the face.
It is one of the few Fantasy-FPS's that was not all cliche, for example there are no lasers or brightly coloured glossy aliens and it is not intended for stupid little kids- infact it's so hard in some places adults can't even do it. (Although christmas 2006 online sucked because of all the little kids- who moved onto games like Halo 3 and ruined their online games!)
The split screen campaign is more interactive then other FPS's in the way you have to resurrect your allies if they fall and you can split up in 2 different directions, thus giving each player a chance to shine instead of being stuck behind the other player and letting him/her have all the fun.
You also get gamerscore for being the 2nd player (Dom.)
The only problems arise from the lack of Gamerscore you can get from campaign- it's mostly online, and the online is much less stable then in later online games like Halo 3 or GTA4 as you (or at least i did!) lose connection several times in a match and you also get put against uber advanced players and get a good old fashioned kicking.
The only problem i had was when you fight Corpser on Hardcore, Marcus -1st person character- kept running in at FULL speed- whilst i was trying to pull him back and not die...
A love of blood, guts and violence is highly recommended for this game!
(NOT FOR THE FAINT HEARTED)