i've tried quite a few fermenters. like most, i began with a bucket, difficult to open, but cheap. mine is now a sanitizing bucket. the large size allows sanitizing most everything in one go.
i have two pet big mouth bubblers, and two glass ones. these i find to be problematic. the old style lid (screw on with gasket) never sealed well for me, and the new style (with silicone ring with 3 flanges) gets pushed out of the fermenter with my active fermentations. the solution here is to put an olympic bar 5 lb. weight on the lid. (the olympic bar has a hole large enough for the airlock). i now use these only for primary for sours.
the glass big mouths are hand blown, and prone to bubbles and flaws. i cut my hand seriously in three places cleaning one (i swear i never even bumped it on the sink... it just shattered in my hands). i got rid of the other one. i won't use one of these ever again.
i have two 7.5 g. fermonsters. i mostly like these a lot. i have two issues. first, the lid can be damned hard to get off. you may want their lid wrench. secondly, if you ever take out the o ring, it can be nearly impossible to get it back in due to stretching. you may want to keep a spare handy.
for secondary, i use pet 5 g. carboys for clean beers, and i use glass 5 g. narrow mouth (machine blown) carboys for long term storage of sours. i wash all carboys with the mark ii keg washer and pbw, to prevent scratching the pet, and to keep me from harm's way with the glass. i also handle all glass fermenters with kevlar gloves. may be paranoia, but after my accident, i don't care. i don't want a repeat of bloody sunday.
stainless steel interests me, but i thought that it was too expensive. after reading this thread, i may try the brew bucket. it seems quite reasonably priced. however, i can't see replacing all 12 of my fermenters with stainless.