ultrasound makes a lot of blocks easily accessible...
i find the median/ulnar/radial blocks nearly invaluable
next is posterior tibial down by the medial mal for work on the plantar surface (can be done, like all blocks, without ultrasound; but why?)...the plantar surface is an extremely painful area to inject locally and the tissue layers are so tight down there that complications of injecting too much fluid can be quite bad
femoral nerve (a bit difficult to get through fascia illiaca and around nerve, but worth it)
i am playing around with sciatic above the popliteal fossa now...once i get a good handle on this, i think it will jump up to number two for most useful
HH