I use 1a.com when I shop online. They carry various items, but I mostly buy electronics. They carry a lot of stuff not available anywhere else in Lithuania. Being an international store, sometimes items take awhile to arrive due to being shipped from another country. Their prices are probably the best I've seen in Lithuania, though not as cheap as Amazon.
When I'm needing protein or supplements I use myprotein.lt. They have good prices, but the delivery takes a long time because they ship from the UK.