The drive from Baghdogra might be tiring (4hrs) but when you reach Gangtok at 5500 ft you immmediately would like to experience the city. The capital infact the entire state fo Sikkim is like visiting a new land ..... completely different from the other hill stations ( and there are many ) in Himalayas. One, the people are different .. not only they look different they are more civilised that those on the plains... On Gangtok city roads you would not find palstic bags ( its banned and no- one mind you ..no one uses it ... ) traffic rules are followed (no stopping of Taxis if its not a designated taxi stop) , they are true people who do not wish to cheat you but would not like to help you explore their mountain state!!!!
It is a comparitively a cheap hill destination ( reaching there might be expensive tough) as the taxi rates and hotels are good and pretty economical. We stayed at Hotel Tashi Delek on the MG Marg ( the main market) and got a great deal (as suite for 3000/- ) and found the hotel to be clean and the food was great. You can hire a Maruti Van for rs 500 per day (exclusive) and visit 10 points (monastery, Gompas etc ) ard. Gangtok. A visit to Nathula is a must . Nathula is open for civilain visitors on Wed, Thurs, Sat and Sun so plan your visit to Gangtok accordingly and also the booking needs to be done in advance (2-3 days in advance, share taxi at Rs. 500 per head). There are many other sites around Gangtok like the Temi Tea garden which is the only Tea estate in Sikkim, Tsogmo Lake (enroute to Nathula) etc for which you would not have to shell out a lot of money.
In total Sikkim is worth multiple visit, its pristine, adventourous and comparitively a economical vacation spot.