I would center the theme around whatever your child likes.  It's about your child, not anyone else.  This year, we did Thomas the Tank engine for John.  We didn't do much b/c he is only two.  If he were older, there are plenty of places on-line that you can order a theme in a bag.

Disney Prince/Princess and Fairy themed were always my favourites:) 

so it really depends on your childs age and if it is a boy or girl. Some of the funnest Birthday parties I've done for children are:

-Little Chef's Party (where the kids got aprons I sewed, got to make a pizza and decorate a     cookie for dessert. Every one got a mason jar filled with flower, brown sugar and chocolate chips and a note on how to add eggs and milk to make chocolate chip cookies and a thank you for attending

-Carnival Party (where the kids got to play games like bean bag toss, I cut out a hole in card board where I painted a clown and they could do there face in therre for a foto, popcorn and a cotton candy

-Pirate themed (we did a treasure hunt, I made pirate hats out of news paper, spray painted a stencil of a skull and bones and they got to decorate them and served hot dogs that looked like ships by sticking schicabob wooden sticks that had a white peice of paper stuck through twice and a flag glued on that I printed out on the computer

-Alice in Wonderland themed wacky tea party...made fruit tea, got mitchmatch cups from good will, decorated with colors, hung up a streamer I made with cards, cup cakes, balloons, tea sandwhiches and let the girls make bracelets and dress up. There are a lot of games you can play with this one- I advise to search it on the web.

-kareoke themed kids party...it was really cute but this was a long time ago when Brittney Spears was big so Ry dressed up like Brittney spears and the themed colors were teal and pink- we made a mini stage for the kids. She was 4 then, I bet you could do the same with Miley Cirus and do other songs from Disney etc...

-70's themed Disco party...fun invintations that I designed with some 60's writing I downloaded, a cute out fit leotard for the birthday girl, bubble machine, bubbles wands glitter, a disco light and some fun music and balloons. Hubballoo is a great game that you can get for the kids to play as well. I also made cup cakes from the box but divided the batter into 6 bowls and put food coloring in each and then poured layers of each color into the cupcake pan- then took a stick and gave eah a quick swirl for Rainbow cupcakes- the kids loved it when they saw the inside!

-Hollywood themed movie party- we rented a projector, got the little "popcorn" boxes from Target or Hobby Lobby, our color theme was red and black with Silver- decorated the hall with red roll paper for a red carpet look, had a picture area set up and also played some movie games (like guess what movie from hearing the music) and also a disney trivia pursuit for kids

And alst but not least: The Rock Star Party for 8 and up. Had all the boys and girls dress up like punky rock stars, with glitter, black nails etc. Had a limo take them to the Hard rock cafe where they had dinner and we ordered a bunch of "virgin" drinks so that they would look cool and then went back to the house where we had a guitar cake and played some Guitar Hero. Fun for fotos- and the kids Loved the Limo ride.

I think the Dora the explore idea is ok, but I find some of the thems like Dora, disney etc, over used, a bit cheesy and cheap looking. I want authentic birthday parties that aren't short of magical. But then again, it's what every your child really wants (and makes them happy) even though I find telling them all the cool things we could do really gets them excited and want what ever theme you've brought up. Once the theme is over both children and parents can't stop talking about how great is it which gives the kids a "cool" boost- which is when it's always good to remind them that you are so happy they were born, and that the world is such a better place now that they are here and you are happy to celebrate them!

Check out http://www.hostessblog.com/ it's one of my favorites for inspiration. Good luck!

I agree go with what your child likes.  When my son turned six we did a fishing themed birthday party.  We didn't actually go fishing but we did a ton of fishing themed activities inside. Over the years we've also done: 

Spirit: Stallion of the Cimarron (dd, 4) - Very cool, lots of horse and western themed activities!

Star Wars(ds, 4)  - before there were SW theme kits and we had to make our own Death Star pinata, lol!

Princess Party (dd, 5) - all of the girls came dressed up, we made candy necklaces, danced, had Belle (a friend) come in costume and read a story, and did crafts.

Beach Party (dd, 3) - our community has a lake with 3 beaches

Carnival Party (dd, 7) - the MOST fun ever!

Spa Party (dd, 8) - so relaxing and fun for the girls

Those were the highlights.  This year my son is turning ten and we're having a Reptile themed party.  As oldest dd gets older she's already talking about karaoke parties and that sort of thing.  We'll see!

hollywood theme party? get everything you need @