The Vita packs the most power, for a pocket-sized device. I like the 3DS for the first-party titles too. Smartphone games have gotten pretty good, but there are three big downsides for me. Lack of physical controls sucks; I hate getting killed just because I put my thumb one mm away from the touch target. My phone also gets absurdly hot (110 - 114 degrees) when gaming for ~30 min, and it makes the device unusable until it cools down. Finally, it kills battery life... and I need my phone to be a phone, too lol.