Ultimate Orange is the best I've ever used. Don't get the Punch flavor though it taste horrible. The only draw back would probably be possible dehydration. It seems to give me cramps sometimes so make sure to drink a little more water than you normaly would.
I haven't used it for awhile but I'm pretty sure its still made. I hope it is because it really helped back in the days when I actually had to work go to school and lift.
Just received 6 cannisters of Ultimate Orange and Punch from www.warehousesportsales.com
$16.00 per unit
The stuff works better than anything else I've ever used for heating up a workout.