I have them all and for some reason my favorite is Fishbowl Racer. It's a endless runner but so addictive. Frogbert is a must also, this has heaps of levels and a endless mode. Beach games has 5 sports put together with each one having missions for a feeling of progression. Superstar Chefs is a platformer with tons of levels which reminds me of James Pond crossed with Bubble Bobble. These are my favourites as well as Traps n Gemstones. But everyone is different and they would surely have other favourites than me. These ones have stood the test of time as I usually buy Donut Games as soon as they are released.
Fishbowl Roll is a quality endless runner... says someone who dislikes endless runners. I like that there are two tiers of obstacles to watch for and a nice combo system.
