Fun Action Packed Shooters?

Rising Storm is very... realistic compared to CoD and BF.

[EDIT] The Far Cry 3 multiplayer might suit you.

Payday? The sequel is about to get released :D
Aside from that Brink and Section 8: Prejudice come to my mind. Don't know if enough people are playing them nowadays, though

Killing Floor maybe? If you are talking multiplayer

Rising Storm was a lot of fun in my opinion. It is a bit slower than CoD or BF3, but a lot of fun once you get into it.

Recomending you TF2, if you not tried it yet. Balance between different classes, high level of teamplay and good community

I have Red Orchestra 1 + 2 for sale/trade if interested

• Team Fortress 2 (a lot of action, fun and everything great plus it's also F2P without losing many possibilities);
• Warframe (pretty fun TPP FPS game with RPG elements such as collecting items and equipment, earning money and so on, also a lot of fun and what is more, it's kinda "ninja-like" game :D );
• Saints Row 3 (really fun and good game, has something similar to GTA series and has coop)
• Serious Sam series (just take a look at gameplays but I think You know or at least heard about Serious Sam)
• Left 4 Dead 2 (really good FPS game with zombies and other creatues; has a good coop mode where players have or at least should helping each other to survive; a lot of action and killing).

Interstellar Marines

Fun? I found BL2's gameplay a lot of fun, with all dialogues adding to it :)

Arma 3 is pretty fun.

You want cheap? After buying CoDs you complain about the price of Rising Storm? Are you fucking kidding me?

Planetside 2

Give Tribes: Ascend a try. It's free. :)

Painkiller Black Edition
EDIT: Multiplayer? Bummer.. The Rise of the Triad game looks good fun

Went in here to flame people that suggest CoD, luckily people are smart, so...

Defiance maybe. More of a co-op thing than a pvp thing though. It's a lot like if you took Borderlands 2 and turned it into a MMO game.

Try Bulletstorm! Pretty fun.

Quake live? free in your browser with a plugin

1) Borderlands 2 - If you liked BL, get this one because it's better. If you hated BL, don't get this one.
2) Space Marine - If you like Warhammer 40K, get this one because it makes you feel like a space marine. Otherwise, you can skip it.
3) Planetside 2 - If you like competitive MMO-style FPS, this is a good one. I dunno about any P2W aspect, but hey, it's free.

Oldies but Goodies --
Shadow Warrior Redux
Unreal Tournament 2004

CS GO

Rainbow 6 Vegas 2 is very nice, with much customization possible in your loadout.

Lots of fun coop FPS games:
Killing floor
Serious sam 3 (if you like it try first and second encounter)
Borderlands 2
Team fortress 2

Oh look, a Serious Sam thread.