Here's what I'm thinking so far - let me know if y'all have any other ideas.
Gang of Four
Three Dragon Ante
Apples to Apples (I'm actually a little iffy on this one, but I suppose it could be played in rounds with people switching in and out)
Trivia cards (for the folks who can't take the time to stay for very long - just stop by, answer a few trivia questions, type of thing)
In other news, overtime tonight, so I won't be at Game Night. Leaving early yesterday means I really like the idea of making up some of that time.