CUR3 - great healing magic, you should definitely get this one
LIFE - very, very important; get this one!
HRM3 - very useful against the Undeads, but not terribly important
HEL2 - not very important at all; besides, the Heal Staff has the exactly same effect

FIR3 - great magic, especially against the Undeads
BANE - pretty useful against Tiamat, but not that important
WARP - good if you want to go back some floors in a cave, but not important
SLO2 - lol, totally useless

To sum it up:

CUR3 / HRM3 / LIFE
FIR3 / BANE / WARP