I think the vote in the House on the marriage equality bill is a good indicator... A state like Texas feels very conservative/right, but in actuality it probably is much less so overall than it feels.
The trouble with House votes (link) is they do come down to one person's feelings, though they risk hearing about their more controversial choices in the next election. While it would seem that SC is relatively moderate with 2 R yeas out of 6, Mace barely made it through the recent primaries and Rice lost by a lot.
While I didn't reference it for ranking, this poll result about approval of LGBTQ nondiscrimination (link) is interesting, with NH > VT, UT for the top 3.
Utah's in the top 3 before MA? That's a surprise.