CTF. Also, I prefer match in CTF levels, because the towers, monitors in the middle and a battle ground in the middle (but hate tree ring zone for this). The levels just seem better if you compare it to the castle eggman match zone (i forget the name) and such. Believe it or not, some people ask me for Match mode in Coop. Does not work. >_> Levels are too big and you can't even find your opponents as a result because they run to the end or back to the beginning.
Anyway, it's always gonna be CTF for me. I like the intense moments.