Of-late, I have been almost exclusively playing Counter-Strike: Source. The bots it comes with are good enough to leave me with no desire to play online, and the weapons have finally been balanced fairly well.
I look forward to the day the designers realise that you can leave a round chambered, fix the re-load animations, and fix the wepon models so that they are not mirrored. Though to me, a rifle with the ejection port on its left side, throwing casings in your face, is so obvious a fault, that I wouldn't be surprised if it is an intentional in-joke by now.
The M-3 shotgun is excellent value, and for whatever reason, always seems to perform better than its expensive, automatic brother, the M-10. The M-3 is so good, when you bag a Counter-Terrorist carrying an M-4, you have to think twice about picking his corpse.
I'm really looking forward to playing Day of Defeat: Source. Hope it comes with decent bots, and I can't wait to get back to sawing Americans in half with the finest of all machinengewehr: MG-42.