After hotTunes was released, I ditched SizzlingKeys for it as my default iTunes controller. The new 2.1 version adds album art display, an option to hide the Dock icon, and the ability to switch playlists -- finishing off the list of all the features I want.

I also find hotTunes to be more responsive than most other iTunes controllers. The effect of the key-combos happens almost immediately, even with a good deal of other things going on, whereas others lag for a second or two.

hotTunes also has AppleScript actions built in, so you can call various scripts if you intend to do something when the song changes, such as upload the track information to a website for display.

Now, I may be a bit biased, as I helped here and there with images and some beta testing, but I did so because I enjoy the program and think it's simply better than the rest. You can't beat the price, either. It's definitely worth a try.