Goldeneye is and utter classic, cant beat that.
For paintball i play Digital Paintball: Source Mod for Steam (you can own hl2, hl2ep1 or css and it will work, or sometimes i think you dont even need a steam game, just steam)
Its only in Alpha stage but its awesome. You can virtually walk the trigger by using the left and right click(so basically double tapping the mouse, which is cool), you can sprint, the reloading animations are with pots and a hopper instead. You can walk about the site while you watch other players play on different sup air fields around you, you can walk up to the shop and buy guns and clothes (although theres only 1 gun availalbe, theres angles and more in the works)
Anyway im gonna shut up about it, as yes i find it good, sometimes its annoying as there can be no servers.
heres the link to the site
http://www.digitalpaintball.net/media.php the pictures lower down are for a half life 1 pb mod.
This mod once done will be awesome.
Insurgency mod as mentioned is cool also, pretty realistic army mod. I love it.