I haven't been to any of those festivals aside from Bumbershoot, which is basically where I grew up. Lollapalooza has always intrigued me, and the past few ACL line-ups have been inviting. I put "other" because my favorite non-Sasquatch festival has to be either Reading of Outside Lands. Probably Reading due to the stacked line-ups they get year after year. The living conditions and the people can go to hell, though.
The only other one I've been to was Coachella '99 and '07... I also went to Woodstock '99. My girlfriend went to 'Roo '08 and wants us to go one year, but we have an obligation to the 'quatch and all of our Quatchers. I'm not sure when we'll make it there, but I'm sure we will one day.
Yeah, I voted Coachella simply because that's the only one I've been to. Shit, I've lived in the seattle area since I was 3, and I still haven't been to Bumbershoot. I'd really like to go to sxsw sometime, but it seems like a lot of work. Honestly one of the biggest reasons I prefer Sasquatch to Coachella is that sasquatch is way more relaxing. WAY more. Coachella was too much work for my tastes, honestly. And too damn hot.