Well, to be fair, a lot of them seem to come with their own intricate lore, which to me sounds like something DF shouldn't do. So if I were to pick mods, I think I'd use mods that are vanilla-like. When it comes to magic mods however, I would be interested if it weren't for the fact that some of them just sound sooooo... Unmystical. They all have this weird sciencey-vibe. And when they use "elements", they get way overboard with stuff like "light", "shadow", "hell", "angel" or some other stuff that definetely aren't elements. I'd rather just wait for Tarn to finally get on the Myth and Magic update, so that we get more intricate lore and a magic system that is a lot more in line with the spirit of the game; weird, intricate, and !!FUN!!
For race mods, and I must say that I am the kind of guy who thinks there just aren't enough races... I think the variants being proposed sound too alien for my own taste, or just not interesting. Plus modders have a tendency to give them starwarsey names, and the actual differences between are so minuscule that I don't even see the point of doing such variants. I hope I don't sound as a bastard, because I really respect the work of modders. They do more than me when it comes to contributing anything to DF. But I'll be honest and say that I don't see the point of adding "sea-elves" if the only difference they have with other elves is that they are sea-weed huggers. Might aswell give elves the choice of praising any aspect of nature they want.
Also, sometimes in race mods, you go from "Elves with pointier ears and masters of magic" to "15ft tall swamp-people with spikey shells, demon wings, four arms, sixteen eyes, a tail with a fire-breathing mouth and they're called the Nhgiksfialy". I know everybody has its own little quirky ideas for that sort of things, but... Yeah, not my cup of tea.
For anything else, guns, more boozes, plants, or furniture... Yeah I'm not against that. I just think I already got a lot to take care of in vanilla DF. So we'll see.