I have no idea exactly what genre that genre fits into.. some of it is a trancey/ambientish. Such as: Massive Attack. Portishead. Sneaker Pimps. Morcheeba. Either way trip-hop is a really good sub-genre if you're into ambient/trance music.
I don't much listen to trip hop but still "lovage" I very much love =) (pity they just made one album)
You know, sometimes I totally forget about Tricky. Ooo Lovage. Aren't they the ones that have that "Sex Am I" song?
Unkle, also good, not sure if it is trip hop though. I think one of the sexiest trip hop-(ish) songs is Feelin' love by Paula Cole Check the lyrics too, hot. Polaroid are another good band, and Nine inch Nails. The ones you listed are all so damn good. My weakness is massive attack, never get bored of their songs. yeh, the lovage sex (i'm a) song is funny, good though. You listened to any Hooverphonic?
Hooverphonic is excellent, but I don't think you could classify them beyond electronica. Too weird and different. I like a lot of trip hop that I've heard, including the ones mentioned in the OP, but I fail to remember any band names. My friend is mad into this stuff.
I think NIN is actually classified as industrial, why.. not sure. I like their older stuff, not a fan of the last few albums. That's just me though. I do like Unkle. And I think Hooverphonic's older stuff is classified as trip-hop. I do like them. Oh Massive Attack is one of my weaknesses too. I can listen to them over and over. I even have "Angel" as one of my ringtones on my phone. Then again, I have Portishead too.
I love The Sneaker Pimps, especially 'six underground'. I recommend people to check out my favourite PsyTrance artist(Electrypnose)'s trip-hop/electronica/down-tempo side project, 'Minimum'.. www.myspace.com/minimium