Which of these festies would you/should I choose?

No Fun: http://www.nofunfest.com/announcement.html
Terrastock: http://www.terrascope.co.uk/TerrastockP ... bands.html

I'd go for Terrastock, but I wouldn't really go too far out of my way for either. Isn't Sonic Youth playing Terrastock?

I'm thinking the same. No Fun literally seems like no fun. Too much noise, not enough variation, therefore no reprieve. I've come to love noise, but I've also reached my threshold with it, perhaps. Terrastock seems to have a lot of variety in its lineup.