A band that isn't really known (?) among the trip-hop crowd and rarely mentioned in these threads, but is more than worth checking out is Antimatter. Antimatter has so far released 4 albums, and first two (Saviour and Lights Out) are pristine trip-hop. Really emotional, melancholic and beautiful. Not 100% pure trip-hop though, as this band really crosses boundaries and comes from a semi-dark metal background. Still, I have had trouble finding trip-hop that I would like as much as I do like Antimatter.
Third album is closer to acoustic folk with still some trip hop influences and fourth album is Pink Floydish emotional progressive rock. All of the albums are great though.
Also, Ulver - Perdition City is an amazing album. Not exactly trip-hop, but very close. One of my all time favourites.
All the previously mentioned albums have a great recording quality as well.