Here are some of the Geek/Gamer boxes I have tried. There are more than this (a LOT more) but I prefer to only list boxes that I myself have tried so you can see the reviews.
1UpBox- $18.92/month. $40+ Value of awesome stuff in each box. Every month features a new collection with an exclusive EPIC Shirt! See Reviews.
GeekFuel- $23.90/monthly. Every box will include a t-shirt, a full game and over $50 worth of awesome geeky goodies to appease the gamer at heart. See Reviews.
Loot Crate: $19.95/month. A box packed full of geeky and wonderful gamer gear, including T-shirts and collectibles. See Reviews.
Loot Crate Firefly Crate- $39.99/bi-monthly. A collection of 5-7 Official Firefly Gear & Collectibles, including shiny figures, cunning apparel and other such finery every 2 months. Valued at $65+.
Nerd Block Classic Block- $27.99/month. A monthly mystery package delivered right to your door filled with nerdy apparel, toys, and collectibles! Every Nerd Block comes with a custom t-shirt (in your size) and 4-6 epic items for you to tear into! See Review.
Nerd Block Arcade Block- $27.99/month. A monthly box full of nerdy arcade related apparel (a T-shirt in every box!), toys and collectibles. See Reviews.
Smuggler's Bounty Star Wars by Funko- $25/bi-monthly plus $6.95 shipping. Each box contains $50 of value in exclusive, high-quality Star Wars & Funko collectible products, including but not limited to apparel, accessories, toys and memorabilia. No fluff, no filler! Review coming soon. The first box ships in November.
SuperGeek Box- $19.92/month (includes US shipping). 40+ Value in each box! New swag every month. Guaranteed exclusive Ultra-EPIC Shirt! or something 2x Epic. See Reviews.
TeeBlox- $9.99/month. One 100% authentic licensed geek and gamer shirt in the genre of your choice (Games, TV & Movies, Beers & Liquors or Hot Meex) delivered to your door every month. You'll also get two extra goodies that could be posters, comic books, decals and/or stickers. See Reviews.
Pop in a Box- Starts at $9.99/month. Get one or more Funko Pop collectibles delivered to your door.
Powered Geek Box- Deluxe- 19.95/monthly + shipping, Premium-29.95/monthly + shipping. Exceptional items varying from the most awesome, epic, amazing, t-shirts, action figures, comics, and so much more. See Review.
*affiliate/referral links were used in this post.