If you're looking for Google corporate merchandise then the Google Store is what you are looking for.
There's plenty of items (the main categories are Accessories, Fun, Kids, Office, Wearables and Doodles), just have a look and you'll find something that you can't really miss!
Furthermore, the European e-commerce store is managed by Merchandise Mania, a reliable company that will ship items immediately and that will solve any problem you may experience with shipping (no, I don't get money for this advertising but I want to publicly thank "Dave" for his helpful solution!).
Pictured below are some items that I already have: