I agree. I think whichever stack you pick will be the "wrong" one for some people, anyway :). What matters is bringing something useful and usable right up front, because if you even can't do that, then it doesn't matter which stack you pick, you'll never get off the ground. I'd suggest picking the one you're most comfortable with, that helps you get things done instead of getting in your way. Once you've proved a concept and gained a bit of feedback and traction, then you can start looking at other stuff, if that's even necessary.
(Full disclosure: I build things using both ASP.NET MVC and node.js: they both have their strengths, and both have their weaknesses). Which one is "best"? IMO, it depends on the context, and what you're trying to do.
Most of my side projects tend to be mobile apps. Find things in the real world that either piss you off or make you wish that there was a better way of doing things. For example, public transport is usually a good source, and any PT company worth its salt has an API you can hit to do something useful with.
Keep in mind that time zones will also play a large part in your development process. Do you have someone who can do a regular eyes-on code review, to ensure that it's being built properly? If so, why aren't they building it?
In my experience, things go really well in the beginning, during the honeymoon period, but as bugs start to crop up and the deadlines creep closer, things start to fall apart when you can't get hold of the people building it because they're asleep in their part of the world, or they refuse to fix something because their interpretation of those tight specs wasn't your interpretation of those tight specs. Make sure you are dealing with someone who speaks perfect English, too. If you can't really understand them in either spoken or written communication, or they can't understand you, don't write just it off, it'll come back to bite you when you have to explain something intricate.
(Full disclosure: I build things using both ASP.NET MVC and node.js: they both have their strengths, and both have their weaknesses). Which one is "best"? IMO, it depends on the context, and what you're trying to do.