What are the best brands for twin tip skis that work well on normal slopes and not just terrain parks

The Armada Ar6 is solid on both groomers and the park, though a bit pricey for some, If your going for something a little cheaper, I'd go with the Salomon Foils, though they can run in the 400's, and if you want to move a step down but still, for me a great ski, i'd go with a K2 possibly the Public Enemy or Fugitive.

Volkl makes some of the best all mountain twin tips. Check out the volkl bridge and volkl wall.

K2 makes twintip all mountain skis

check them out at k2skis.com