Pix The Cat - I got so obsessed with chasing the high scores in the main arcade mode I had to give it up, luckily the nostalgia mode is arguably better, then there's the lab and...
TxK - For many of the same reasons as Pix, I love the trippy colours popping out the OLED, the awesome soundtrack (Noise Pulse) and everything this else that seems to help me get into that flow zone. You can tell Minter has been trying to perfect the game for decades.
Rogue Legacy - I suppose as I enjoyed the many many hours I put into it but I can't help feel it was too reliant on the grind.