So, I had a Moto G (1st gen) and it was destroyed by pool water a few days ago, now I am looking for a new phone. Considering HTC One M8, Moto g (3rd gen), and Samsung Galaxy Grand Prime.
Welcome to Android Central! I'd probably go for the Moto G. It gets universal praise for being a premium quality phone at a budget price, and is newer than the aging M8. From what I've seen on these forums, the Galaxy Grand phones tend to have more problems than the Samsung flagships, and they probably won't get much in terms of system updates.