I feel that Siphon is a necessity when it comes to shotguns, since chances are they're going to be dead soon so why do you need a d.o.t. effect, and also that you've probably taken damage getting that close, so healing is definitely a priority.
I like the VOT Fragger personally. Looks cool and reloads 2 at a time for a pump gun.
\m/ (O_o) \m/ Alan Wake deserves a full sequel. Xenosaga Deserves a full sequel. Dark Cloud deserves a full sequel.