Ans - depends on the PC I'm using (SSD size) and the purpose of the PC; see my 'More Information'. Yep games suck-up a ton of space. For most Gamer's I generally recommend using their SSD for their OS + Apps + Working data and use a HDD for their Games. The couple disadvantages for HDD's are: 1. Mini-save LAG (pauses) and 2. Load times, and the disadvantages for SSD's are: 1. Cost and 2. Limited space.
More space: You can RAID 0 your '256GB' SSD i.e. a second for 512GB capacity, clone the data, and recopy to the RAID 0. Note: (no TRIM and RAID 0 is more risky)
Locations: The 'problem' is if you have a Steam account, the games all reside in the 'Steam folder' and in one location, by default it's your (C
drive. You can opt to move the folder to your HDD; see -
https://support.steampowered.com/kb_article.php?ref=7418-YUBN-8129
Also, if you simply move the game or game installation from (C
to your HDD you'll need to re-install the game(s).
Things to consider: In my case, some (few) are installed on the SSD e.g. BF3 but most are installed on the HDD and all Steam games are installed on the HDD. Further, if the Game requires Steam then it's going to install in the default location.
Some folks have a dedicated SSD just for their Steam.