BoardGameGeek has a section on the profile page for Hot Games. This section is difficult to fill in because (a) you need to enter the ID of the game, which is OK as long as Die Macher is your only hot game, and (b) I don't know what a hot game is anyway and Aldie has declined to tell me. I have been experimenting with determining my Hot Games using the BGG XML API, but with little success.
Undoubtedly rating a game highly correlates positively with it being hot. I also find that my hot games are ones that I've played recently. So I have tried adding my rating to a factor based on how recently I played the game. By this metric, my 10 hottest games are Rheinländer, Shadows over Camelot, Blokus, Elfenland, Bazaar, Domaine, Amazonas, Geschenkt, Arkham Horror and Battle of the Bands. Hmm... it didn't come out *so* bad.
Where it seems to be falling down is on games I am a little bit bored with. Rheinländer is definitely my hottest game of the moment - I played it for the first time on Thursday night and think it could well become a favourite. However Shadows Over Camelot, although it is a great game for a big group, doesn't hold many mysteries for me. So I tried adding an extra bonus for games that I haven't played very many times. The hot 10 then becomes Rheinländer, Bazaar, Geschenkt, Arkham Horror, Medici, Torres, Great Ballon Race, El Grande, Elfenland and Shadows Over Camelot. There's still something missing there... Medici was an interesting game, but I don't particularly aspire to be good at auctions. Not sure how to encode that at the moment.
I think my hot 10 is "games I want to play most right now". That means that old games, even great games, are not hot. New games that I liked are very very hot. The hot games are the games that I read about when I surf the 'geek. I'll continue work on determining them automatically and let you know when I make the breakthrough that allows me to read someone's mind.
Anyway, here's my real hot 10 that I would enter at BoardGameGeek if I could get a connection: Rheinländer, Bazaar, Arkham Horror, Torres, Trias, Evo, Ra, Cathedral, PÜNCT, Web of Power. But not necessarily in that order.