My partner and I enjoyed our Holland America Alaskan cruise a couple years back, and we'd always wanted to see Scandinavia, so we signed up for their 12-day Baltic cruise.
Now, most others we know in the gay/lesbian "community" (I hate that word but it does the job) look at us like we're nuts when we say what we've done. After all, there are cruises that cater to gays exclusively. But these tend to be "party" ships that aren't really what we're looking for 24 hours a day.
This cruise lived up to our expectations -- not more, not less, which isn't too bad.
Makes great use of a smallish space. Just right for two people. Plus it was quiet, clean, pleasantly decorated, and the bed was incredibly comfortable.