I started with Roguelikes again. My favourite by far is
Powder. The beauty of the game is the simplistic nature. It's all randomly generated and no 2 games are the same
(The more I explain it, the more it sounds like Minecraft. Don't worry they're completely different.)
You start off on level 1. You have to scrounge around for equipment and food, killing any creatures in your way. Once you feel ready, you look for the descending ladder to level 2. The aim of the game is to descend to level 25 of the dungeon and defeat the boss battle. The twist is, once you die, there's no loading. You have to start over again. Surprisingly, it doesn't get boring. I've died over 10 times (it's incredibly hard, in-fact, you're not
actually expected to get to level 25) and it doesn't get boring because each time you start again, there's new monsters, new encounters, items maps etc.
Lots of fun.