I am big on games played just for fun, not with a winner getting a prize at the end. (Even if you make sure that everyone gets a prize.)
That said, I like pictionary. You do not need the actual game. In fact it is better to gear this to the age of the child. If the kids can't read yet just pick a category like animals.
Kids love, and I mean love, charades. Not like we used to play with all the complicated gestures for "one word, two syllables." Just give them a category like "t.v. shows," and watch them act them out, hysterically funny and you'll get great photos too!
One year my son, he was about 8 had an "alien" themed party. We cut out a cross shape of paper. The sides of the cross were the arms, the top the head, and the bottom (just that one long strip, not two) was where the legs would go. We folded in the parts. First everyone drew the head, then folded it over so you couldn't see it. (It was folded down.) Then someone drew the arm (or arms it is an alien) on the right side and folded it in. (My son had drawn the tummy part in the middle.)
I didn't think this would go over well at all, as some of the kids were very artsy, and some were not artsy at all. Well, 30 minutes later they finished! Then they were passed so that everyone got the head they drew, and all the parts were unfolded. Oh my goodness the boys loved this!
I always do this yarn thing. There is one color of yarn for each person. You take that yarn, one color at a time, and twist it all over the yard (or inside). Everyone has to follow their yarn, round and round, everywhere. The end was always the outside (garage) fridge where the cake went. (Again no prize just cake time.)
We always did a scavenger hunt, but at each place they first had to answer a question about the birthday child ie. what is his favorite dinner, or book or whatever, and then the birthday child reads the next clue.
Pyramid building. Who can blow the biggest bubbles. Hope this helps!!!
Remember when you are playing to have at least 2 more activities then you think you will have time for. Sometimes the games move quicker than you thought they would.
Oh and skip the whole goodie bag thing. No one needs "little junkers" as my friend always called them. A nice big candy bar with a bow, a little
Lego set.... are much better received. One year we gave each of the children a helium balloon. Truly, little things are appreciated.