What's missing from your question is what your abilities and desires are, where you live (and how willing you are to relocate), and exactly what you're looking for.
You can look at the various lists of job openings, or for that matter your local job board, to see where most of the jobs are. That's probably your best bet if you want to maximize the chance of getting hired right now (although you can get blindsided by competition - if everybody goes with that plan, there will be an oversupply for $POPULAR_LANGUAGE
and it'll be easier to get hired in $LESS_POPULAR_LANGUAGE
). This can also vary widely by locality.
It's no guarantee of a good salary, though. You'll be competing with the shallow end of the programming gene pool, and the salaries are likely to be based on that. Something less common but more technical is likely to boost your salary, should you be competent at it and should you find a job.
It's also not necessarily good for long-term employment. Where do you want to be in twenty years? If you stick with the currently popular languages, and aren't prepared to move from there, you're likely to be stuck with low salary and dull projects a decade down the road. You can learn more difficult and varied languages if you want to try to future-proof yourself.
If you have ambitions for a start-up, consider what you'd like to do, and what's best for that. In a start-up, you have to be able to do a tremendous amount of work, so you want efficiency, and you can use pretty much any language and environment you want, particularly if it's a web-based approach.
Also, realistically, how able are you? Can you master technical subjects and outshine your competitors, or are you rather average and hope to live within the herd? Do you love writing software, or are you looking for a well-paying transition to business executive?