Avoiding party goers - No chance of that in Vegas The best you can do is pick the right hotel (not a young, rowdy crowd), make sure you're not going during a spring break week, and avoid hotels/casinos with "hot" clubs after dinner.

Avoiding mobs of people -Again, no chance of that in Vegas. Go here and try to find a week with a relatively small number of conventions in town.

Avoiding walking on the strip - The Deuce seems to be a better option than the Monorail.

Avoiding casinos with scantily clad dealers - I think you'll need to stay away from PH for sure. Palazzo/Venetian/Wynn/Encore/Cosmopolitan don't seem to have any of these.

Avoiding casinos with scantily clad servers - I'm not sure if there's any casino where you can find this. It's all a matter of degrees. I've never been there, but you'll probably want to avoid Hooters

Spa - I've been to the Canyon Ranch spa @ Venetian/Palazzo many times. Great service/facilities.

Nice rooms - Palazzo/Venetian/Wynn/Encore/Cosmopolitan all have fabulous rooms. Cosmo is the newest hotel, but Wynn is in the process of refurbishing all of their rooms. But even their old rooms were fabulous.

By HL, do you mean high limit?