@M_Six - your day definitely sucks. I want to thank you for making me feel better about mine.
But seriously, that sucks.
Since everyone else is sharing their airline experiences ...
I used to travel weekly for work (~50k/year), now it's just the occasional trip. I was Star Alliance Gold and took United and US Airways pretty much exclusively (I'm upset US Airways is now with American). I went out of PHL and connected through ORD, IAX, DFW 80% of the time. TBH I experienced very little in the way of issues with any of the Star Alliance carriers and they were very good to me on numerous occasions, Republic Airlines especially. I got bumped to first class several times with a coach ticket before I even had Gold status (United's rewards program is the best of the bunch in that regard). I remember getting delayed in IAX due to a massive thunderstorm. I switched my flight at the last minute to another United flight leaving for PHL; naturally I got stuck with the row 27 middle seat. They handed me a first class upgrade as I boarded.
The worst things that happened to me, which are not nearly as bad as what happened to some of you:
-Boarded a tiny Canadair regional jet in Atlanta as a thunderstorm rolled in; sat there for three hours with almost no A/C (cabin door closed, couldn't deplane).
-Had a flight PHL > IAX > Albuquerque; never made it to IAX on time, next flight out put me through Phoenix and then to Albuquerque. Arrived at 3am and had a client meeting at 6am.
-Stranded in IAX going to PHL; my morning flight was canceled and I stayed an entire day there and didn't get on another flight until late the next morning.
-Was going through security as I learned my flight was canceled (always fun, happened twice).
So, not too bad.
The one airline I refuse to take is American because they still use the McDonnell Douglas MD80s. They're ancient relics with the worst cabin layout and are quite loud inside. I'll take American again when they mothball those abominations.
Another plane I won't take is a 757. Airbus A321's are far superior; quieter and more room. I'm a relatively small person and even I feel confined in a 757 let alone someone 200+ lbs.