You know... i was actually gonna come in here and suggest this one

We bought it at Walmart on a road trip in an "emergency" and we were thinking about returning it when we got home, but it worked so much better than our old Monster one, and was actually really convenient, so we just kept it, and it has been serving faithfully for over a year.

But the reviews on amazon are awful, so im sure there are better choices... it worked/works for us though.