I have a Samsung 840 Pro 256GB as my boot drive (windows and some software) and a Cruscial M500 256GB as a "games" drive (amazon black friday, 80$). Plus the 2TB hard drive for most programs and games and photos. External drives for more photos, videos, tv series, movies and backups (2x2TB, 3TB, 1,5TB and 500GB).
And that's it. HDDs for me mean storage space and less critical software and gaming. My Windows 8.1, after a year of use, boots in 7 seconds. There's no way I would buy a new PC or laptop without a SSD.