I don't know what you're budget is, (or what is available in India); however, if you favor dark blues, you can NEVER go wrong with Visconti Blue. For a little less money and a little more ink, I'd also recommend Diamine Midnight or Blue-Black, (but be advised that both of these inks lean more to black than to blue).
Also available in India, I THINK, is Quink Permanent Blue - it isn't as rich as Visconti or as dark as Midnight - but it is cheap, readily available and has a nice blue color. What is more, it has EXCELLENT performance qualities. Make sure you do not get Quink Washable Blue - that fades out as you write - much like the stuff you have and do not like.
EDIT: Hopefully others will chime in, because I just recalled from a while back; I think India may not get the good Quink Permanent Blue, there's a couple of different versions of it floating around I think. If you can get the one that is made in France, go for it.
Hope this helps.
All the best,
Edited by corniche, 09 September 2013 - 08:20.
Catholicism is the law of life, the life of the intelligence, the solution to all problems. Catholicism is the Truth and everything that departs from it, one iota, is disorder, deception and error. - Juan D. Cortés
Catholics Come Home.org