Bad Date: I'm sure Christmas holds sentiment for a lot of couples, but you can't expect your guests to toss out their own traditions to spend the day celebrating you. Other holidays to avoid New Year's, Mother's Day, Father's Day, and Thanksgiving.
Bad Timing: Make sure your wedding flows well. If you're planning on photographs between ceremony and reception, make sure there's entertainment for your crowd. Fill the time gap with a cocktail hour, hors d'oeuvres, or musical guest.
Boredom: To hold even the shortest attention spans, keep your ceremony short and sweet as guests will be ready to launch the after party. Keep speeches to a minimum and spend a short time, sans mic, individually thanking your guests for being there. My favorite receiving line includes cake.
Seating Arrangements: Some people should never be allowed to sit together, like exes or trouble makers. On the same token, don't sit anyone next to the speakers that can't tolerate loud music all night. Just pay close attention to who you are seating with whom and where and you should be just fine.
Bad Food: My biggest fear. Just make sure it tastes good and there's plenty of it. Ranking right next to bad food is no food.
A Cash Bar: Let's face it, no one wants to pay for their drinks, especially at your wedding. However, in the economy now, it can be hard to come by a couple thousand dollars to sufficiently liquor up your crowd. My remedy is to have an open bar for X amount of hours only {estimate with two drinks per person/per hour}, after time's up it becomes a cash bar. If guests want to wake up with a hangover, you aren't going to stop them, you're just not going to foot the bill.
No Direction: "Where is the.... ?" If your venue is spread out, it's easy for guests to get lost. Use sign posts to clarify where the good stuff can be found like the dance floor, booze, and bathroom.Invitation Confusion: It's likely that single guests will question whether or not they can bring a guest. Please address envelopes to Ms. Smith & Guest. The same goes for children; Mr & Mrs. Smith and Family. It's also likely that if your wedding is going to encompass a meal time, that some will wonder if they can expect dinner. On your invite, please make some identifiable note, ie: "champagne reception and dancing to follow" or "dinner to be served at 7pm followed by dancing".
Putting Guests to Work: There will be some things that only a guest can do like greet others, take gifts, etc, but you should want your guests to enjoy your day with you. Why else did you spend all that money but to have a good time with the people you love most? Hire a day-of coordinator to tend to the details of your day that makes it all run smoothly without enlisting the help of guests.
No Thanks: Some will tell you it's okay to skip the favors, but I think each guest should take a little something as a thank you. A hug and a five minute conversation at your reception just isn't enough if they flew a million miles to party with you. I like to suggest that newlyweds host "morning-after brunches" for out of town guests.
You cannot please all of the people all of the time. Plan in advance the needs of your guests and allow yourself to enjoy your day. Shrug off the little things that didn't go according to plan and show off how happy you are!
