Penn Championship
I get them at Costco for like 28 USD for 15 Cans.
Great on Hard Courts.
And not bad of a price.
Penn Championships stink depending on how unlucky you get. Poor quality control, and if you arent playing on a clean court they will get pretty close to unplayable by the end of a match.
I was using some the other day because I forgot to bring balls with me so we had to go to the Walgreen's to buy some, and they were practically gray by the time we were done.
Normally I use US Open. But I think the Dunlops Grand Prix are nice as well and I prefer them myself, but some people on my USTA League team like US Open better so I get those.
If Im going for cheap, I buy the Wilson Championship balls, they cost the same as the Penn and seem to be more or less all the same.