Which guest are you? (please don't tell me I'm sexist. These labels apply to both men and women and I tried for a fair distribution....)
1) Mr. Filofax: He calls on on Rosh Chodesh Cheshvan for a meal invitation on Tu B'shvat. He dutifully marks it down in his appointment book but you won't and you'll totally forget about him until the Thursday night before.
2) Mr. "Hayom Yom What L'Shabbos?!?": He's the guy who emails around midnight on Thursday night asking for a meal invitation and after you tell him that he can come, he'll tell you that he's got three friends sleeping in his apartment this week that need a meal too. He might then cancel Friday morning because one of his friends invited him to go skiing at the last minute.
3) The Shopper: This guest will receive an invitation from you and ask if she can "get back to you". She will wait until the end of the week to decide which of the three invitations she has received over the next several days is the "best one" and accept that one.
4) The Educated Shopper: She'll ask you outright "Who else is invited?". If she doesn't like the rest of the guest list, she'll likely tell you she's "busy" that week. The Pushy Educated Shopper will tell you who else you should invite along with her.
5) The Powder Room Pair: They only accept invitations as a couple. They are the same sex.
6) Veggie Heaven: The lacto-ovo-vegetarian who won't mention this critical piece of information until he calls Friday morning for your address. He casually says that he's "sure it's not a problem....".
7) "O.A. is an Allergy" Girl: She's on the Overeaters Anonymous program. She won't want to mention this so she'll tell you that she is allergic to wheat, sugar and eggs. She'll bring her own spelt challahs and ask you for the ingredients in every dish at the table.
8) The Wandering Jew: He's the guy who gets up in the middle of the main course and starts scanning the bookcases. He'll find a volume of interest and have a seat on the couch. His plate will still be piled high. If you begin clearing the course, he'll tell you that he's not done eating yet. He often sings to himself during table conversation.
9) The Hungry Anorexic: Self explanatory... She will take the LARGEST serving of everything on the menu, proceed to cut it all up into tiny pieces and eat one bite of everything. She will help you clear the table and pronounce as you are scraping the hefty contents of her plate into the garbage that "Everything was delicious". Zemiros will be extra long that week, as she will spend a protracted amount of time in the ladies room.
10) Mr. "My Momma Raised Me Right!": He'll compliment every dish as it arrives at the table. He'll take doubles of the burnt rice because nobody else touched it. He'll send a beautiful thank you note after Shabbos.
All you hosts and hostesses out there - feel free to add your own!