Hans Lolich island has a beautiful safe anchorage on the N. side.
Magens Bay is a wonderful anchorage and beach.
Hull Bay is worthwhile and has a great beach hangout.
Inner Brass has a protected western anchorage.
Santa Maria Bay has incredible snorkeling.

These are located on the North side of STT and you must be aware of the Atlantic swell conditions in most cases - that is true in STJ and the BVI too.
A circumnavigation of STT is a wonderful week cruise - Water Island and Buck Island offer very good overnight anchorages as well, the West side of Hassel Island is good too.
<img src="http://www.traveltalkonline.com/forums/images/graemlins/smashpc.gif" alt="" /> <img src="http://www.traveltalkonline.com/forums/images/graemlins/smashpc.gif" alt="" /> the rest of St. Thomas can be skipped your not missing anything.
I feel that is very unfair - I have lived and sailed in St Thomas for over 40 years.
Like many of the places in STJ --- plan to eat on board more often -- but there are some beach bars and restaurants accessible.