1.I used to subscribe to Live 365 since they have tons of homemade radio stations and some other good stuff of every variety. They have several station that just plays Anime theme music and other cool varieties. I should get back to them; it's worth the low monthly fee.
2.I have satellite television and that has xm radio stations programmed and that helps. They have a few genre stations that I like and they display the music as its playing
3.Being a subscriber to Yahoo! Launch is great, too. The ranking system is a great way to find music that you would like and they have a large selection of stations to choose from. If you could incorporate the autoscrobbler to that, it would rule, I believe.
4.I also love searching for radio stations from around the world on the internet. You can go from Korean pop to Greek dance with just a click of the mouse.
5.Our local college station has a great variety of listening but not every dj has the same taste as me so it's a crapshoot.
6. I do use recommendations from critic guides like allmusic or even Mark Prindle but sometimes they get it wrong like Re/re said.
The easiest to use is Yahoo! Launch but I recommend any kind of streaming radio station on the web. It is the greatest thing that the world has invented in the last 10 years IMO.