We have had parties at both.
At Toys r us there are different themes that are great and the kids love it. Once was okay but still fun for the kids and the other was Great, depending on your host and their enthusiasm as with anywhere.
They help with passin out the gifts, bagging them and writing down who they were from. You can choose various things to include in your package. The play area is a plus to before the party starts and we even stayed about 30min after. I would recommmend this since we havent had a bad experience and all you do is relax, they pass food, cake, do the games/crafts or whatever is in the package plus the gifts and clean up. You can even take what leftover pizza there is if you ask for it. Since you did pay for it.
Now Planet pizza, it is good as well and my kids loved it, the pizza is not that great in my opinion but its okay. The rides are fun for them and they have a great time. If your child is scared of rides you can ride with for free. But if you think he may not like the rides it would not be for you. The rides are kind of loud and may not be good for kiddos too young.
Also, chuck e cheese is great, both of my kids love going there as well,
and there is a place in Frisco that is great too.I cannot recall the name right off but they are by the mall close to Ross etc. They have games and rides as well. they have a merry go round, bumper cars, and the boat but a little smaller one and movie a room. We love this place and so do the kids, they have a small train outside that goes around the parking lot before you go in that the kids love, and the food is better that any others esp if your like us with more adults than anything since them being still so young, they have alot of pastas a great salad bar and they have icees for the kids which food for us was a plus since 80percent was adults.
Well I hope this helps. Even had a bday at burger king on the west side of plano and it was cheap , and the kids loved it as well. There is a little table in there just for their size and you can choose the meal choice. We took a few games for them like pin tail on donkey etc. It wasnt over 60dollars . Good luck. Have a blessed day and enjoy wherever you decide, I hope he has a wonderful bday.