Not for the squeamish, Gangtok's cheapest foreigner-accepting crash pad has rooms accessed by miserably dark, decaying stairways. The nasty dorms close May to October due to damp: bring a mat to put over the hard, ancient mattresses. In contrast, however, six front-facing rooms are far better than you'd expect, especially room 502, which has great views and a functioning shower.
In other rooms hot water is by bucket. The mouldering 'secret' rooftop has great party potential. Check in at the restaurant fronting the road or, if that's closed, at the billiard hall on the 2nd floor. Unusually, prices are not seasonal.