trade euro, plenty of liquidity, excellent leverage and it can get pretty wild at times ... all you want lol
Imo, CL is a crazy whore while ES, NQ are classy escorts. They're all out to screw you out of your money but CL is more difficult to trade imo, but it offers "plenty of action". You could also trade interest futures (10 yr note), they're reasonably predictable over the long haul imo.