What do you hate about United? I use them internationally, and they're pretty good. I've never had a United domestic (USA) flight that went as planned though.
I use them internationally and domestically, and the planes are uncomfortable and ugly on the inside (seriously, if I'm going to be on a fucking plane for 8 hours, everything better be bright and happy and those flight attendants had best be hot) not to mention LOUD AS FUCK, the pilots seem to be the masters of rough landings, at least a third of my flights are delayed or cancelled, and the movie selection sucks ass on a regular basis. Not to mention the fact that United hasn't gotten on their plane-painting game in years, so those 777s you fly around the world look like they're ready to fall apart. Not reassuring for someone who hates flying with all of his heart.
All that being said, I'm a PREMIERE EXECUTIVE FUCK THOSE LINES, BITCH I'M GOING TO THE FRONT member, so many of those problems are avoided a lot of the time. I still hate United though. Flying JAL when I go to Tokyo in August, and that's the bottom line.