Fun thread!

My worst seatmate experiences were both both smell oriented.

#1 Back in college I got stuck in the middle seat of 5 on a packed flight next to a backpacker returning to the US after a seemingly shower/toothbrush-free two week tour of Europe.

#2 On a BA flight two years ago ORD-LHR, the man next to me (Peterpack?) incessantly and regularly broke wind the ENTIRE TRIP. I could set my watch to it. Not only was it noisy, but it was hair singeingly horrid smelling. On top of it, the plane had an electrical problem and all the lights (reading too!) were stuck on all night. At least the blanket I threw over my head to block the light filtered some of the stink. The turtleneck sweater I pulled over my nose that still had some residual perfume smell on it helped too.