For years I've just cast aside the military shooter genre. I've seen them covered to death all over the web, commercials, magazines, etc, but they never really interested me.
A week or so ago, I saw a deal for Call Of Duty 4: Modern Warfare for $7, and I realized that I already had a free copy of Battlefield 3 from some Origin promotion months ago, so I...
My experience with most FPSs is limited to the Xbox 360, and have only in the past year or so made the transition to PC. I'm finding it difficult to get the same precision with mouse/keyboard due to the years I've put into the controller mechanics, so if a game offers controller support (which I believe these do?), I take advantage.
Of the two series, I pulled away from COD and started to favor BF sometime after COD:MW2 came out. I loved the first Modern Warfare (I think I only Prestiged twice, maybe three times), but the design of the later games went too frenetic for my taste. The difference between COD and BF is similar to the difference between the Tony Hawk games and the Skate series. One is more of an arcade, fast action experience, and the other is more realistic. Nothing wrong with either, but my taste at the time was bringing me to Battlefield. I was really interested in the Black Ops series, though. With what little I played at a friends house, I was tempted to jump back over, as I'd caught a glimmer of that original Modern Warfare feel, but I never jumped. Instead, I abandoned the military shooters altogether in favor of what was going on with Halo. These days I'm on my PC more, and can't get enough of games like Blacklight: Retribution, and Planetside 2. Planetside 2, especially, has an amazing community, partly because the game reinforces that by emphasizing and rewarding coordinated attacks as a team, which is all I really want out of a good shooter.
Really cool that you are revisiting these, Travis! Now that you have COD4 on PC, you might be interested in the Star Wars mod that is out there, called Galactic Warfare ( http://www.moddb.com/mods/star-wars-mod-galactic-warfare ). It's a complete re-skin and rebuild of maps and characters, sounds and everything. It's pretty amazing!