I've been to so many showers (started when I was really young - my sister is 17 years older than I am!) and our family/friends have seen just about every game out there. I try to do something "different" when I host a shower.
1. The MTB takes a tray filled with small baby related items around the room...showing each guest what is on the tray. The hostess tells everyone to take a good look (that is ALL she says). The MTB then walks out of the room (and stays out) and the hostess asks guests to answer questions about the MTB. What color is her outfit (pants, dress, top, etc), did she have on earrings, how many, rings, how many, necklace, anything in her hair, nail polish, what color, shoes, what color, etc. etc. The person who gets the most right wins.
2. We also do one where we send aroung a roll (or a couple) of toilet tissue and tell the guests to take as much as they think they need. Some people take 3 squares or less and some take 20 or more. After everyone has their tissue...they are told to make a bow out of it. The MTB decides which bow looks the best.
3. A couple of easy ones are word scrambles and guess the number of Q-tips in a jar or baby bottle.