So this one is my favorite!! They have 4 albums worth of mashups totally free absolutely no catch. The mashups are fun and I like listening to them for the first time while I'm out running because it's always a surprise to see which artists they mash up. Pretty funny but definitely explicit content since they use rap music a lot. Some of the albums are separate songs while other albums are one long track. The long ones are fun because the songs/mashups mix into each other but the separate ones are nice when you have your music on shuffle.
So you do have to enter an email address to get the download but oh well. These are remixes of the original tracks so they are just a little more workout friendly.
Same company as the one before but just different free songs/remixes
This links to one of the free albums of mashups I liked but they have a lot more on the website
Free 60 min track. Has 3 different options for beats per minute/intensity. You do have to enter an email address. It's free but I wasn't a huge fan of the mixes.