When a game is finished cause my opponent mates me or resigns, I like to thank him for the game (most of the time :-).
Unfortunately, it is only possible to message your opponent when making a move. It would be nice if one could send a final message to their opponent at the end of the game (directly, so not via selecting your opponent from your game list and click Send Message).
Grtz, Bart.
They might not even check the game. I send a PM saying "Good Game!".
Don't worry about the PM... it is for good reason. You have a good idea, but I don't think it will work.
Now people will check the game before they archive it and it may or may not say "Good Game". A PM that says "Good Game" is better!
I am even sure a lot of people get beat and don't even go look to see if someone made a win-move and said "good game".
P-