The OS goes on the SSD for paging (if used) and just loading up the OS.
The largest games are ~100GB on the drive. You (and I) have a 1tb SSD. Are you going to have more than 5 large games installed? 5 large games would represent only half of your SSD. If not, don't worry. Even if you are peaking 750MB, you shouldn't have to worry. I don't think I've ever had more than 5 major games installed on a computer.
If you have the chose, put the ones with annoying loading screens on the SSD and the rest on a HDD. media goes on the HDD.