I used to use a JXD960, absolutely perfect- solid state so no wobbles, took big SD cards, had a nice big screen and it weighed nothing. But then I crushed it to bits trying to squeeze it into the underseat storage of a Honda CBR600 (it turns out they have none, I was trying to fit it into the fusebox)
But it was very good while it lasted, and cost buttons. JXD do millions of players, not all of them have av-in though. You might want to find one with a removable battery too.