Originally Posted by bvds

Plain Jane. One-second duration, nice resonant reverberation, and pungent odor cloud with a nearly instantaneous 5-foot radius. Your standard, everyday, friendly fart.

Beefy One. Sounds loud and butch, e.g., 'BRAAAMMPPP!' Smells like a cross between a decaying meadow muffin on a hot day and a fresh dog-turd.

Eggy. Smells very much like rotten eggs (or hydrogen sulfide). A powerful odor which tends to put people off lunch. Often rips out in the fashion of a Bunbuster (see below).
Fireball

Bunbuster. 'BRAAAP!' Sounds something like a Beefy One, except much more sudden and much more powerful. May smell either eggy or beefy. Leaves your asshole smarting. You really feel these babies.

Ripper. Sends seismic ripples to the next town. Rips the seams in the crotch of your pants. This fart genuinely hurts, and you can still feel it 20 minutes later. Anyone sitting nearby may experience hearing loss.

Originally Posted by bvds

Diesel. Sputters to a start, but then keeps putt-putting along spewing out an endless cloud of dirty, noxious fumes.
Surprise! You didn't even know that it was there, but suddenly . . . 'BRRMP!' Yellow surprise

Gunshot. Sounds just like a gunshot. Unbelievably loud indoors. Hard to believe that this emanates from between your buttocks. Bullet explodes into billions of virulent odor molecules. Gunshot farts are relatively rare but, like guns, very dangerous.

Squeaky. Puny and unsatisfying. Sounds a bit like a muffled 'Wheeeek,' but smells foul.

Worrier. The kind that seems to be a fart right up to the point at which you release it. At this stage, matters become less sure, as it feels too solid for comfort. You go to the bathroom and check your underpants at the first possible opportunity.

ToiletPoopie Prelude. It feels like it's going to be a large beefy one, but out comes a tiny little squeaker fart plus the head of something massive. You tense your buttocks fast, lest you give birth to the brown equivalent of a zeppelin.

Present. The type of fart that seems harmless, but then brings a small poop as a housewarming gift. You shuffle off to the toilet and give thanks you weren't in a business meeting or job interview when it happened. If you were, you're screwed.

Burble. Bubbly! Sometimes messy too.