I have been to both. Kaunas was the former capital of Lithuania, and is an industrial city, with very few 'tourist' sites. But that means lots of local contact and very few tourists!

I think you should go to Vilnius (the current capital). There is a lot to see and you can find nice cafes to relax in as well. The old town is particularly attractive, but you should also see the former Soviet holding centre (almost opposite the Parliament building on the main street) to get some idea of Vilnius' sad past. You can do a day trip to Trakai Castle which is worth a visit.

Do enjoy yourself and go before it gets far too westernised!

There are a couple of topics you may find useful HERE and HERE.

Pippy

Hello, I have post same photos in this forum about Lithuania. You can see them here

Also been to both Vilnius and Kaunas and I agree with "alsacienne" (go there before it gets far too westernized :)) cause this country is growing very fast.
In my personal opinion you should visit Vilnius, but actually Kaunas is also a very nice town. But, if there still will be nice weather on you visit to Lithuania I recommend you to go to The Curonian Spit, cause if saying the truth, this place is really tremendous, but as I mentioned it's my personal opinion. Of course if you like noisy nights and lots of entertainments go to Palanga (only in summer), where you can party all night (I would not recommend it for family vacation. Too much noise).

So, have a nice vacation!!!

A small correction (as am myself from Lithuania). If to be precise, Kaunas is actually a so called "temporary capital", this city was the capital for only a short period because of military reasons. Vilnius was founded as a capital city in 1323, and from that time has always been a capital except for short periods when for reasons such as polish occupation, etc. it was not possible to have a capital in Vilnius.

i,m kind of planning to go to vilnius for surgery.
is surgery of a high standard?
is it possible to rent apt.,and what sort of price should i be paying.

is surgery of a high standard?

It is in general in all Baltic states, if you are careful. Because there are many uneducated doctors. It can be very dangerous.

Never, never choose a doctor unless you have been refered to him by someone you know.

If money isn't the issue, I'd look for a doctor in Moscow. Some of the world's best doctors work in the Sklifosovsky Institute. It is kind of emergency unit but you can always have a personal consultation (for big $$$).