If you're playing with/against players in Pakistan then there is (extremely) little to no lag at all in any game. For that, you need at least a 512 Mb internet connection.
From what i hear, PTCL and Worldcall are best for Xbox LIVE.
I think Wateen's Cable net in Lahore doesn't cut it either since i have been playing Halo 3 with a few players in Lahore, and a couple of them were experiencing lag; they were on Wateen's 1 Mb Cable net. Other players who had PTCL had no lag including myself...