I agree with your list here. Already have some RIPPLE and NXT and will buy more in 2015 for sure, for the same reason you do. I'm not convinced of Stellar tbh, but NXT and RIPPLE will surely rise when their implementation and features start to catch on.

Ripple is really working togething with the banking industry (which is also a reason for concern) but their main strenght is their network of course.

NXT has the overhand when it comes to features (assets, voting system, monetary system and so on...) onlu pity that so few online shops accept it for now, ... but then again they're only been online for one year and a bit, so no surprise.

In 2019, the NXT will have evolved fully and we're going to live in a world where cryptocurrencies found a way to be as fast, easy and secure as fiat currencies, with the extra of being more reliable and less prone to 'printing money' by the governements.  It's just the next step, we went from cassette tapes over CD's to MP3 in 10 years... we'll evolve from paper money, over debet cards to crypto in the next decade.