Entertainment in Lithuania is diverse and quality, but relatively cheap. Regular spectator events are especially cheap: major league sports and opera prices start at ~3 EUR, but you may expect good deals elsewhere too. Lithuania excels in some particular types of entertainment: basketball spectating, countryside tourism (with various traditional activities), indoor alpine skiing, scenic hot air balloon flights, sandy beaches. Foraging (berries/mushrooms) in summer/autumn and under-ice angling in winter are other local traditions you may try.
Urban entertainment: Culture, Nightlife, Sport
Traditional culture (theaters, opera, concert halls) is concentrated in the city downtowns. Theater plays are mostly Lithuanian while the music is more international.
Best nightlife is in the downtowns of Vilnius and (less so) Kaunas/Klaipėda. In sunny summers Palanga resort outcompetes urban clubbing, with its Basanavičiaus street becoming one large crowded multi-stage gig area every evening.
"Modern entertainment", such as cinemas, bowling, and pool, are most easily found at the largest shopping malls of the main cities. Each Akropolis mall also includes a public ice rink. Some casinos are also in the malls, but many are in the downtowns.
Top spectator sport in Lithuania is basketball, the modern city arenas (constructed for Eurobasket 2011) providing local team's home games. Main city teams play world-class international games while small town teams are limited to the local major leagues. Football stadiums are smaller and the game itself of worse quality.
The arenas also host irregular major concerts, although in summer they move to open air (parks and stadiums). Moreover, out-of-city music festivals are especially popular in summer.
There are no permanent theme parks but temporary funfairs visit in summers. Two large indoor water parks exist in Vilnius and Druskininkai (Druskininkai one a bit larger and famous for many saunas). Year-round indoor alpine ski slope in Druskininkai is among the world's largest.
Mind-based activities have been gaining popularity in recent years. Quizzing became a serious issue with a sport-style team participation and all-Lithuania final games of key "leagues"; some paid Vilnius quizzes offer English translations. A smaller craze is the escape rooms (where a team has to get out as quickly as possible, solving puzzles), all accessible to non-Lithuanians.
Lithuanian cities are known for their greenery and many parks, many pristine and unlandscaped.
Recreation: Nature, Parks, and Active Tourism
Merely 1-2 generations ago most Lithuanians lived in the countryside. Perhaps this is why urban Lithuanians are fond of natural recreation to this day. Foraging (mushroom and berries), angling and hunting are traditional entertainment (the last two require permits). Recently it was done for subsistence and if you wouldn't eat the fish you caught you would still raise quite a glimpse. Many Lithuanian city-dwellers even own suburban agricultural land plots where they enjoy growing food, but this is something a foreigner wouldn't experience.
The five National parks are the best introduction to Lithuanian nature. Roaming is generally free of "private property" signs as they are limited by law. Some rivers are popular for kayaking, while lakes offer swimming opportunities.
In 2000s new forms of recreation were imported from the west. Numerous adventure parks sprung up all across the country to offer easy-to-difficult tracks and ziplining. By 2006 the first 18-hole golf course has been laid (now there are five near Vilnius, Klaipėda, and Druskininkai).
Lithuania is a lowland country, so some forms of recreation such as alpine skiing and hiking are limited, although possible (unimpressive ski facilities are available in Ignalina, Anykščiai, Vilnius, but only some days are cold enough for them to operate).
Extreme sports have also been rapidly growing in popularity since the 2000s. Lithuania received multiple wakeboard cable parks while its coastline attracts kiteboarders on the windy days. Small waves are not good for surfing, however.
Countryside tourism is a popular form accommodation among locals as well as a location for various feasts (family, student and corporate). It means converted or purpose-built farmsteads that offer traditional countryside life (saunas, outdoor hot water baths, lakeside beaches, farm animal contact), while some also have more elaborate entertainment (horse riding, ponds for angling, boat rental, etc.). The fact that Lithuania was urbanized relatively recently gives both authenticity and local popularity to countryside tourism.
Flying is a hobby for relatively many Lithuanians, with a network of "aeroclubs" offering airplane and balloon scenic flights and parachute jumps. Lithuania is among the world leaders in per capita hot air balloon numbers, their flights largely unrestricted.
In the seaside resorts there are opportunities for boat trips to the sea or the Curonian Lagoon and one may also rent water bikes. Sunbathing is however the main activity for tens of thousands resort visitors as the beaches are all sandy, wide and free-to-use.
Summer bike rentals are available in Vilnius and the resorts, which also have a great network of bicycle paths and footpaths.
Many companies offering active recreation lack English websites. It is possible to order through a travel agency but this may increase prices several times. It may be the best to come up without reservation in such cases, although this is possible only in some places (cities/resorts). Some shopping malls sell "present cards" which you could then exchange into entertainment.