Plex is great for this, especially because it automatically updates your library when you add stuff; plus, it keeps track of where you're up to in a series and what you've already watched.
I've done a bit of research. If SSDs become cheaper, what advantages would SSD have over HDD, if any? According to my research, SSDs are smaller, faster, last longer, and more reliable, so price per byte really seems to be the only thing going for them. Feel free to correct me, as I don't claim to be an expert on this.