If your looking for a quick trip away and don't have someone who wants to come now is a good time to book carnival. They have over 50 sailings where you can book any cabin with no supplement. I have a list but don't want to copy/paste someones blog post verbatim, but on carnival you can search for single traveler prizes so it's easy.
All are to Bahamas, Caribbean, Mexico region from 9/20 through December 15th.
If you want the see the list google "cruise resource blog", it's the first result.