I'm a nightmare. I take/have...
Spare bass, head, guitar strings, gaffa tape, drumsticks, hi-hat clutch, bass drum pedal, mic, various cables, tools, batteries, plectrums and for two gigs, a spare snare drum after the drummer forgot his. I also usually take two sets of clothes to change into for functions in case our singer's hubby ( our sound man) looks like a sackofshit.