If you're into shooters I highly recommend (if you have access to internet) Ghost Recon: Online. That has been a personal favourite of mine. Another thing to go with Minecraft is the technic laucher. It has multiple modpacks that are basically instantly installed. The packs you can find are amazing. You could too always browse the free games selection on steam. At the very least you can even resort to torrents (not recommended although it is fairly handy).
TF2, but I think you're set with Minecraft and Goat Sim lol