Massive Attack use a lot of bass, though they are not for everyone. Trip-hop, supposedly...I dunno, I like them when I'm in the mood to relax and/or feel some bass (relaxing to deep bass doesn't seem to make a lot of sense, but a lot of the music is laid-back). They write a lot of longer, moody songs which are all pretty bass heavy, but some that stick out are:
"Angel" (from "Mezzanine")
"Inertia Creeps" (from "Mezzanine")
"Butterfly Caught" (from "100th Window")
"A Prayer for England" (from "100th Window")
"Name Taken" (from "100th Window")
Both Mezzanine and 100th Window are great albums, IMO. Their album "Blue Lines" was recommended by Paul Messenger in the Stereophile Records 2 Die 4
if that means anything. His description of their "style" is right on.