I love music. Most of the music I love is hardly on the radio - but this is the Internet! You can find everything from Petticoat Junction fansites to people selling toast on eBay. I've been to quite a few online radio sites in my quest to remain firmly entrenched in the 80's.
Live365 is good, and used to be really great. They definitely have the widest variety of songs and genres - some that I didn't even know I liked! Nowadays, they still have the genres, but the site itself is too hard to use. For one thing, you can't have a pop-out player anymore. It's stuck on one side of the window, and you'll need to keep the whole window open. Also, you can't easily change from one preset station to another anymore with the drop-down menu. That was one of my favorite aspects. I used to "change the channel" during the many, many ads. Lastly, the signal isn't so great. Songs will frequently fade out as if you're going through a tunnel.
AccuRadio is the site I'm most frequently on. The best part about this site is the ability to ban artists, songs, and albums you don't want to hear. The reception is great, the songs play with no buffering at all! You can also pop out the player, save your favorite stations, and make "mixes" of several different genres combined into one station.
However, the stations themselves tend to repeat songs. You can skip all you want, but the more you skip, the more ads will play.
I just found radiotuna the other day. The variety of different genres and available stations featuring those genres is ASTOUNDING. Not only can you "bookmark" a list of stations, you can also bookmark genres and individual artists. They also have a downloadable desktop player and website widget.
You can't skip songs or block ones you don't like. I haven't played with it enough to see how many ads there are, or how they work. Some of the stations are actual radio broadcasts, so there's probably a few ads.
I've used AOL radio in the past. Because it's the least customizable, I don't use it as often. The heart symbol means you either like it or you don't; there's no ratings. However, this is the only site that I have found Wild Orchid on! There's not a lot of variety outside of that, though. Also, no pop-out or new window.