The only pedal I can think of that I absolutely couldn't do without is my old DoD Bi-FET Pre-Amp, and the only reason for this is that the pickup in my Epiphone acoustic is one of the old skool Fishman passive piezo's (Thinline 332).
All of my other pedals enhance certain aspects of my playing, but aren't absolutely needed.
Rob Smith
I AM the bass player!
GUITARS: '93 ZON Sonus 4, '85 G&L L-2000 (Mahogany), '05 Schecter Stiletto Custom 4, '06 SX SJB-62MG (Fretless), '07 Squier Bronco (project), '06 Ibanez AEB10E-BK acoustic bass, '70s Epiphone OO-sized acoustic, '94 Peavey Reactor (extreme makeover edition)
AMPS: '03 Ampeg BA115 bass combo, '86 Peavey MkIV Series 400 bass head, SWR Workingman's cabs, 2x10" & 1x15", '00 Peavey Micro Bass