If you don't rely heavily on your preferences and don't need to trouble yourself with backing them up, it's easy to delete them without going into the file system by holding down ctrl-alt-shift while the program is starting up. A pop-up will ask if if you want to delete your preferences. If you click OK, everything will go back to defaults. I believe this works for all Adobe products, and many of them have similar problems with bloated or corrupt preferences that can degrade performance.

edit: This won't delete any independent assets, such as brushes or patterns, only remove them from the active palettes. The assets themselves will still be in their proper folders ready to use when you need to load them up again.