I just got back from Prague last week and as a gay destination, it wasn't that impressive (as an old, historical city though - it's fantastic!) We went to Friends which was fairly quiet mid-week, Real Club which had a naked/underwear party with 3 attendees (and an empty labrynth downstairs) and Drake's in Praha 5. All had some kind of seedy element to them, so it depends what you're after! I'm sure on a Saturday night the places heat up a bit better but Prague itself has a disappointing 'worn' feel to it with the influx of British (& other European) tourists. Just my point of view.
STOCKHOLM is wonderful. I went there in 2003 and had an amazing time. Picturesque, friendly city with a somewhat small but excellent gay scene. I thought the bars there were great. Caught some funny drag shows, met some people (the crowd was very friendly) and generally had a very good time. A little on the expensive side but nothing like Switzerland or London.
Happy travels!