Including PC?
1. Halo 3
My most favourite online multiplayer of all-time
2. Halo 4
Had some problems to get into it the first weeks but I play it daily and love it right now. I think the "big" differences to older Halo games was also why some other people didn't get into it. If they would have played it more I think they would also like it now.
5. Halo Reach
Was fun but wasn't as much fun as Halo 3. Liked the small maps more as the small Halo 4 maps but I still prefer Halo 4 right now.
4. Battlefield 3 on PC
played around 150 hours which is not much compared to Halo but much compared to other online games for me and played pretty much only conquest. Not sure if I even touched Deathmatch. But from one to the next day I lost the interest, something which never happens with Halo games for me.
5. Ghost Recon: Advanced Warfighter 2
If for co-op campaign, co-op missions or multiplayer against others, I liked all of the online modes. And I was one of the best in the worldwide leaderboards which was also cool because these leaderboards didn't only count the most kills but how you played against other people around you in the leaderboards.
