Mystery Game Wednesday and Steam Saturday never really worked out, at most on either of those we had 4 people. I think it's safe to say that we've cut those from Game Night at this point.
As for Team Fortress Friday, it happened last week with some success but this week there was just nobody around. The problem is, when it's just Me, Andy and Jubs playing (as it was a few times), it gets pretty dull. There is just a lacking interest now to keep it going every week. If we actually got the numbers, meaning at least 5/6 players, then it'd be worth it. It's just a matter of actually finding those players.
I can't really comment on Mario Kart Monday as I'm not really involved, but I assume it's the same problem as with Team Fortress 2.