NIRANJAN

I have 3 days work at Frankfurt. Taking family along. we have seen Zurich, Munich and Venice before. This time we would like to cover other places in two weeks. Kindly suggest places to visit. We don't mind travelling to different country. But it should not cost us too much. We appreciate your suggestions in terms of itinerary , location to stay and train details.
Thanks.

Man_in_seat_61

Well, Frankfurt to Paris starts at just 39 euros each way in 3h45 by high-speed train, centre to centre - www.bahn.de/en

Frankfurt to Amsterdam takes about the same, also from 39 euros at www.bahn.de/en

Sleeper train to Vienna? From 49 euros with bunks in a 4-bunk couchette, ideal for families, www.oebb.at

Berlin? From 29 euros, www.bahn.de/en

Bamaman

If you have two weeks and want to see Paris, London and Rome, you can see them all. Just combine fast trains and budget European air carriers.
Take the train to Paris like noted above.
Go by Eurostar to London in 2.5 hrs. or less.
Fly London-Gatwick to Rome FCO in 2 hrs. on EasyJet.com cheap.
Then fly home from Rome.

PalenQ

location to stay and train details.>

check out these superb sites to get a fix on European trains - Man in Seat 61 who posts above - his commercial site www.seat61.com and www.ricksteves.com and www.budgeteuropetravel.com.

when are you going? If in summer or warm weather then consider Switzerland for a week or so - could easily combine with a week in Paris or Italy - Venice would be tops on my list - Rome is much farther down the boot - but there are overnight trains from Munich to Venice and Rome. Save on travel time and the cost of a hotel.

PalenQ

Copenhagen is also a night train or day train ride away and there is a lot to see and do there - if kids are young trek over to the original Legoland in Billund.