Beautiful pics , You should go to Trakai if you have a chance too, there are guided tours which will take you there by bus. It's beautiful in winter.

For food and drinks I recommend one of three Šnekutis pubs, they're all within walking distance in the city centre, you'll find genuine Lithuanian beer and food there.

As for other things, it depends on what you like. Quiet bars, loud parties, museums, shopping, walks in a park?