I've hardly played most of the mode actually.
I prefer elimination, then DM and TDM (though TDM sucks on developpers maps, you can't play with random spawn points like in TS1, in the end, there is like only 25% of the maps which is used...)
there is more a sense of accomplishment in elimination, since you end up the last man standing.
I tried vampire, but I found that health go down too quickly (but I'm not sure how high the bloodlust was. sure, I can get a lot of kills quickly if everyone stay in the same room all the time, but it's not the case on every maps. and it's just lame when there is only one opponent standing and he is at the other end of the map, you just have no choice but to die. that would probably work better in a regular DM)
I've hardly played bag tag (except on TS1, where I got the world record twice on each bag tag challenge) but that seems pretty good. with the right setting it's fun trying to survive against 10 guys. probably one the best modes.
it makes me think I should maybe try gladiator as well. I think I haven't played it since the last time I failed the world record on zany zeppelin
but if it is somewhat like bag tag, it should be good.
I'm not especially fond of virus, but it's good for a change. it seems to be popular amongst less skilled players, maybe because you can get easy kills?
can't say much about shrink, thief and monkey assistants...
it's kind of a pity that they removed regeneration and leech (well, I played leech mostly) they could have kept them, not as game modes, but as options.
there isn't much point in playing CTB against bots unfortunately, but against human players, it's probably one of the best modes.
I've never been into zones. you just keep running from a zone to another, just because your allies bots aren't able to protect them... in another hand, if they could, maybe it would rely too much on camping... though, I suppose it could work well on a linear map.