This is a list of my current favorite blockchains not because they will make you millions or anything but because i think they are developing really influental and or interesting technology. Btw i wrote this at 2:30 am so please excuse any nonsense or spelling mistakes
etherium : if their was a "killer app" blockchain i think etherium would be it. Etherium took the idea of bitcoin being a big computer quite literaly when they made a way for anyone to write decentralized programs and even new tokens in fact some of the following are made with etherium
decentraland : built with etherium this technology will allow you to own your own virtual land and your land will support the ability to run code as well meaning you could for example have a vr store that you can design a 3d object then pay to get it printed simple example but imagine the possability who knows maybe your next job will be in decentraland
namecoin : i actualy wasnt sure wether or not to include this one as i havent heard much about it but what i have heard sounds amazing the use case i heard for this was replacing the dns service and adding a new extension called .bit meaning for example you could have a .onion site and a .bit domain meaning instead of looking like http://3g2upl4pq6kufc4m.onion/ it could look like http://duckduckgo.bit pretty cool
slock.it : slock.it is bringing the smarthome to the etherium blockchain using an example i heard them use in either an interview or a talk your smartlock could rent itself to someone they then use the house for an agreed price then your lock could pay you and pay a cleaning service to come clean for the next guest
storj : i belive storj is now on the etherium blockchain storj is a way to rent out your extra hardrive space you can also use it to rent space from to store your files maybe those embarasing high school photos you love?
i dont know what will come of these blockchains but they are very interesting and i hope the concept for each succeeds