Build something really big. Like a tower, or a castle, or just add to your home and make it look nicer/bigger. You can also play around with redstone, farming, branch mining, go on youtube and watch other people play to get ideas. There's TONS to do :tongue.gif:
Plus with mods, challenge maps, multiplayer, there's even more to be done.
1. Download the latest Weekly Snapshot
2. Go on Creative Mode
3. Use Spawn Eggs to spawn tonnes of Villagers
4. Surround them with TNT
5. Activate the TNT
6. Watch the mayhem unfold and laugh manically
Try doing adventure maps. You could also download the TooManyItems mod and make a cool contraption. Also you could expand your house to make it EPIC! Another thing is to play with redstone or learn a bit more about redstone wiring. :biggrin.gif:
Lol... what I do is find a way to get anything I wanted with ease.
Make a mining system, make a few farms, go watch youtube videos, get inspiration, build more houses...
On my singleplayer I started with basic buildings for fun with stuff I needed. Farmed loads of diamond and iron and stuff. Something that I found fun was making mushroom houses. Gather loads of mushrooms, stab a bunch of skeletons, and make bonemeal to grow the mushrooms super huge then put walls around them. Also, trap sheep inside of them
Oh and I also made a hotel, even though I'll be always alone.. And I also made a roller coaster ride : P And even if you think something is done... screw that and expand it bigger!
EDIT: If you have friends, play multiplayer with them. That can be loads of fun.
A fun thing to do is go in creative mode, build small houses with lots of doors, surround the are with fences, and spawn lots of villagers! The amount of villagers per house is based on the amount of good doors, so as long as you have lots of doors, they'll keep cramming inside.
Build a spleef arena, and play spleef with friends or zombies! Dig a 1 block wide hole from the surface to bedrock, fill it with TNT, blow it up, and enjoy the hole! Go on a monster killing spree in the night!