for my Outdoor (aka really loud make sure I hear it in a loud background) ringtone I use an MP3 of Robin William's opening monologue from the Good Morning Vietnam soundtrack, at max volume. It also works very well as an alarm clock sound.

Obnoxious as hell, but for times when I want to make SURE I hear the ring, it works great.

for the rest of the time, my current ringtone is Dire Straits Walk of Life, at a more normal volume.

I've got a Nokia that has USB, IRDA, and BlueTooth connectivity options and built-in MP3 player, so I can download MP3s to the phone (1GB RAM) and use any of the them as a ring tone, as well as using the phone as a backup IPOD.

I don't understand the "pay $$$ for a ringtone only" concept. If you want to use music as ringtones, just buy a phone that supports MP3s and downloads from your computer. Cheaper in the long run and a LOT more flexible.