I'd say FFA or MTDM. When i've played them FFA's seem to be full of noobs that can't play and MTDM is the same. I usually avoid normal TDM's because 1 in every 5 games I meets a 5 or 6 man clan and they usually end up spawn raping the feck out of my team of 6 random players.
As for SnD, you get some noobs in there but it's the gametype iplay 90% of the time and you getsome noobs who get a kill and jizz at the XP they get but 70% of the players in SnD know what they're doing.