All three of the cameras you are interested in have been reviewed by Steves Digicams:
Imaging Resource also has reviews of the Canon and Sony, and preview images from the Panasonic:
Based on specs and test shots, I'd say the Panasonic is the best all-around.
Help! I'm currently using an old Canon SD600 and while I don't have major problems with it, I'd like to upgrade to something with a bigger screen and a less clunky build. While I like to mess with settings once in a while, I'm no great photographer and barely ever change the ISO settings or the exposure times (see, I don't even know what that's called!) unless it is a night shot on vacation or something.
Crisp pictures, won't be blown up over 5x7 (probably over 4x6, really)
Good pics in low lighting (sad to say, usually at bars and of goofy friends) which includes not having a flash so strong it turns ppl into ghosts!
HD video, but this isn't a must.
These are the models I *THINK* I've narrowed it down to, but of course, when doing too much homework, you always find negative reviews somewhere. (Also not many reviews at all of the Panasonic FX75.) I've always had Canons and have enjoyed them, but I'm don't want to blindly stick with them if there are better options out there. Any suggestions? Also, if I'm missing some model that might be a better fit, let me know...