I have a confusing relationship with Boss-- they're difficult to love, because they're the most widely distributed (and popular) stompboxes in the world, which makes a pedalgeek look at them kind of like a motorhead looks at the Honda Civic. Though I always chafe when someone makes the (very common) claim that Boss is "the best there is!", and I have little love for their tend towards the generic (how many more vanilla distortions are these guys going to churn out?), they have made some classics... or at the very least, some good, solid, well designed pedals. I like all the Boss pedals I own, but the trend is to discontinue the interesting pedals and leave the most uninspiring ones in production (DS-1, anyone?)
DD-5 Digital Delay
DF-2 Super Distortion/Feedbacker
HR-2 Harmonist
FV-500L Volume Pedal
NS-2 Noise Suppressor
OC-2 Octave
PN-2 Tremolo/Panner
PSM-5 Line Selector/Power Supply
SYB-3 Bass Synth
WP-20G Wave Processor
(If you're interested, my last rant about Boss pedals is here)