What kind of vacation are you guys looking for? Keep in mind, I am a city person so I have no idea when it comes to small towns/outdoor adventures but here are my favorite city experiences..
BEACH WISE?
Miami is fun during december. You get the beach and the weather is nice (Warm, breezy, not too hot. perfect beach weather) Plus it's very popular in december so plenty to do and lots to see, Miami is a fun city.
SAN-DIEGO, Cali. I really enjoyed my time in Cali
plenty to do (the san-diego wild animal park is a must see) great restaurants, lovely beaches (although the water isn't very warm! lol but they have otters)
THEME-PARKY/ACTIVITY WISE
Can't beat Orlando, FL. Universal, six flags, Disney world, Epcot, Water parks.. it's like the themepark capital of the world
Atlanta, GA. Usually this wouldn't even be on the list but the Atlanta aquairum is simply amazing. It's one of the biggest in the world, they even have a whale shark!! Check it out on youtube. amazing. amaznig.
JUST PLAIN' OL PRETTY
I went to DC to see the cherry blossoms and thought that was really magical.
BEST OVERALL (If you like cities)
You can't beat NYC. Especially in the fall. Central park is beautiful, weather is perfect (fall orange weather), lots of shows, lots to do.. it's new york.
I wouldn't go in the summer or deep winter though.. personally.
FUN IN A CHEESY KIND OF WAY?
Vegas. lol drinking, shows, gambling, plastic awesomely tacky fun! I went with my parents (so mind you, my experience was quite PG-13) but got to see some AMAZING shows (Cirque du soleil will blow your mind), amazing restaurants and I really did enjoy myself in all it's tackiness lol
Oh and don't forget to check
http://www.tripadvisor.com/ !! You don't want to ruin your vacay with a bad hotel..