I recently decided to switch to a bluetooth Apple trackpad as my primary mouse device thingy. Considering how useful gestures are on Mac OS and whatnot, it works out a lot better nowadays than a regular mouse. I'll have to keep the old one around for the occasional Windows venture.1
Fullscreen mode is also pleasant when I have only one screen (which if I've been playing Dark Souls, I've hooked my other monitor up to the PS3), though I still insist it's a fairly useless mode on Mac OS. Without proper multi-monitor support, it's pointless, as you'll inevitably end up with a single monitor displaying a cute textured background. However, Mac OS has had pretty good virtual desktop support for a while, and it's still plenty useful. Switching between them via the keyboard is less than pleasant, though, so gestures come in handy there.
The only other mouse I have is an old Logitech mouse -- not sure what kind, it has no name printed on it -- and it's bugging out at random. The poor old thing will randomly begin resetting itself at times, and I've never figured out what triggers it. In addition, the USB dongle to connect it is incredibly weak. Its range is fairly limited, and it's very easy to interfere with the signal (placing any object in front of it usually does the trick). I've had to keep fairly unusual dongle placement just to maintain a persistent connection. For example, using an extra USB cable to plug it in and hang the dongle over the top of my secondary monitor.
Windows hates trackpads. ↩