Test Track for sure. Have a back up plan though - when we were there the first week of July this year, it was EMH morning at Epcot and we were waiting at the International Gateway at rope drop, walking with the front of the pack to Test Track. We were surprised to see a line already as far back as the drink stand next to those restrooms. The main front gate guests had gotten there be fore us, but that's not the issue as we knew that would happen - the point is that TT had a delayed opening that day, and didn't actually open until around 8:30. No one had been allowed into the building yet which is why the line appeared so long. When they made the first announcement at around 8:05 that TT was on a "delayed opening" today (no other explanation), lots of people bolted out of line, presumably to run over to Soarin. We stuck it out because that was our only chance to ride TT during our trip (we had Soarin FPs for another time). I'm glad we stuck it out, but during the announcements they made periodically while it was closed, the CM made sure to say "we aren't sure when or IF we will be opening today." All of that is to say, if you really want to ride TT be sure to have a backup plan - apparently it has a "delayed opening" rather often.