Heres some good songs for you to download. Not just bass, but good songs in general. You can find them on Beatport.com for about 1.50 a song. Well worth it if you love trance music, and you can listen to half the song before you buy!!!
Some of my fav's:
Above and Beyond vs Andy moore - Air for Life (awesome song)
Ave Mea - In the End
Jay Wave - Samasara
Dogzilla - Your Eyes
Dogzilla - Without you (HUGE hit single)
Jose amnesia vs Fedo - I need you
Josh Gabriel - alive
Lang vs Gareth Emery - X equals 69 (THICK bass in this one)
Try those and see how you like em!