This may sound funny but I have the store up and nothing to sell.
I tried t-shirts for a while but it didn't really work out.
I have to confess your post made me laugh.
But here are my five cents since I continuously create in my mind a word where everything becomes a perfect business (yes, my head is really full of fantasy, now you can laugh at me ;) )
This suggestions are based on what sell the most on local auction websites, and as a matter of fact, it could also be a good starting point from you, paying special attention to "top seller" items and "popular items": you should check ebay and other similar.
MP3, MP4 portable players, including video.
SD Memories, all kind, all size, all capability.
Video games, specially the portable ones
As Lev Ge mentioned, Cell phones and cell phones accessories
T-Shirts: I think in your country there are lot of niches about thematic T-Shirts, so find out which one people near you find interesting
Collectibles: Dungeons and dragons carts, all kind of manga and anime cards are quite appealing for a very specific (and in some way "limited") market, but it is a really good business.
This option is the easy one since you will be offering something offered by a lot of other people.
The second, most challenging option is to find, or even to build a new product or service and offer it... although that's really hard yet not impossible.
I think you have proved you are very enthusiastic about new projects (you already have a running e-commerce site!), so you can use it and try different options, always having on count your resources and the things you enjoy.
But the more important thing: no matter what your business is about, always be very concerned about the quality of the stuff you sell, and also be very careful about the customer support you provide, be honest!: remember the way you like to be threated when buying something, and then go ahead and provide twice better customer support on your site!
Best of luck with your choice!
Regards from Colombia