I need a good site to store and share my blend files. I opened account in blendswap yesterday but there is something wrong, I can not navigate to ‘my profile’ (shows me eror 404). And Came to know about another site SketchFab! Which one of them is better from all prospect?
Blendswap and Sketchfab are two different things. On blendswap your blend file is available for others to download and open in blender. Sketchfab, or the other similar sites allow your model to be viewed online on their site or embedded on another site. As far as I’m aware the actual blend file is not available for downloading to then open in blender. Which you use depends on what you are actually want to do.
Oh I thought they are same 
So sketchfab is like a showcase, like youtube! Well that’s not what I want. I want something like blendswap, where I can store and make my blends available to download. So this is the best in its field?
Use both. You can share your blend from blendswap and you can embed the sketchfab viewer on the blendswap page (I think, blendswap has just undergone a pretty big re-design recently, lots of changes).
I’d say Blendswap is the best out there for Blender.