If you've ever seen how quick and deep glass cuts, or would like to avoid the experience altogether, you'll want plastic buckets ($) or Better Bottles ($$) or Stainless Steel Corny's or Fermeters ($$$).
I like the lighter weight of the plastic buckets and BB's--lifting and transfers are easier. I always put the airlock on last (e.g., after the bucket or BB is in the fermentation fridge) to prevent sucking the fluid within the airlock into the fermeter. The airlock is always first to be removed before transfering or moving the bucket or BB from the fridge. The BB has the advantage of allowing one to watch the mesmerizing fermentation process.
Cleaning: No brushes on plastic buckets or BB; Just hot water, oxyclean soaks, and wipe off with a yellow sponge (no scouring pad). My first BB has scratches on it from having used a carboy brush on it during my unenlightened days--I have noted no ill effects on any subsequnt beer batches from the scratches so long as normal santitation measures are followed.