I've used tor and Torpark...
Torpark is great because it uses USB and everything stays on USB and all temp stuff is deleted once you end a session,with a mini Firefox app.You go through a series of routers which add layers of encryption on each hop and pretty much forget the last route/hop the data came from....and the routers change dynamically every however many minutes.
The downside is that it is slow...but is definately secure.If you have a keylogger etc on your machine then it's pretty much useless.