I'm not really nerdy anymore, back in the day I was huge in to Pokémon, still have red, blue, emerald green, and another (fire red?) somewhere.
Handful of years ago I sold my yu-gi-oh card set for 500+ dollars, put the money towards a guitar haven't looked back.
I still play my dads old original game boy games, I'm in love with radar mission. By far one of the greatest games ever. Then there's nemesis (believe that's what it's called, been a while with college).
Used to play spyro (the little purple dragon). I have all the games from the PS1 to the most recent PS3 game. I used to sit down and play it with my dad when I was younger. Miss those days a lot.
A while back I dabbled in WoW, wasn't really my thing. I prefer games like Kerbal Space Program, empire total war etc now. Recently picked up castle story off steam, good game to kill time on, needs some work tho.
Can't forget Skyrim, and Battlefield. Still play those from time to time but I don't have next gen tech so I can't really play much more. Just cant afford the upgrade being in college.
Oh yeah can't forget about minecraft and terraria either...
I play a lot of board games that are Harry Potter or LotR based. Though I play a lot of board games in general tbh. Except monopoly, my family would probably kill eachother if we played that... But that's about it for my nerdyness. I geek out when talking about supplements and the gym with people tho.
I spend more time reading about gym related stuff than I do studying for college. Can't help it, it's just enjoyable. Most people can't read through journal studies or lab reports but I kinda like them. Guess that's why I became a personal trainer, just enjoyed talking to people about the gym.
As for collections, Calvin and Hobbes decorate my room and my laptop wallpaper. I change the wallpaper to match with the seasons... I have every single Calvin and Hobbes book known to man that I could get my hands on when I was younger. Same goes for The Far Side Gallery and Dilbert...
Lego set collection as well, mostly Star Wars but also some mars stuff and TONS of castle set stuff from a castle series legs did. Just picked up a collectible Beatles Yellow Submarine.
Other things that adorn my room walls include 3 glued together picture mosaic Peanuts puzzles. An old callender from 2013, a tag wall (take tags from stuff I buy and pin it up there, includes Corona, coke, Pepsi, alpinestars, tags from places I've been, Star Wars tags from shirts, Harry Potter tags, and many more).
I also have a huge Star Wars collection of books and logo sets with Star Wars colectable bookends (3751 out of 5000 made).