Shoutbox

-Takes far too long to boot up, uses way too much ram (I might as well say my 2gb computer is 1gb when using Vista)
-The new start menu is rubbish I liked it better when everything just nicely popped out (yes I'm aware you can change the Start Menu style, but that changes it completely and gets rid of the recently used programs and whatnot)
-The Visual style for it is rubbish, and all the Visual styles i can find for it get annoying after a while, or just don't work for me at all (so more of a personal thing there) - plus building my own style is way too hard (I've started but from a number of Googles getting transparency on my style isn't gonna happen without a lot of work)
-A number of the programs I use don't work (well) under Vista causing a number of headaches trying to find simple and efficient alternatives
-Everything by default is in LIST VIEW! I hate list view I like tiles/icons view, and it's very annoying having to change EVERY SINGLE FOLDER! I found one way I could change the default folder template but that didn't really seem to achieve what I had in mind

Umm yeah that's all I can think of at the moment. There are a lot of positive things I like about Vista too, but some of the positive things one way or another can be replicated back in XP or any other operating system.

EDIT: Oo, the bootloader! It's like a war between XOSL and bootmgr on my computer when I ever need to change something drastic with Vista. Took me 8 days to sort out the last problem...