Well, from all the avvies I have had the current one is the one describing me as a Tolkien fan the best - it looks like the Tree of Gondor on the one hand, since I am a fan of Gondor and also like Telperion, since I have always somehow liked Teleperion. Since my sign is Leo and Teleperion is connected to the sun, I guess that kind of makes sense.
And the TM initials just stand for my name - The Might... pretty simple really.