I do not own many. I usually only play classics on Steam. I usually only played BO2, MW2 and sometimes BO3. It can be fun but at the same time, it can be boring because not many people are searching for matches on Steam.
from steam i got 38 games, also some other, "unknown" games, then i got WoT, WoWS (world of warships) and some other i dont play that much, but also some privat servers (world of warcraft etc) at all. i own ~ 50 games (and i dont play even 1/4 of them)
I tend to buy all my games on steam as it's my preferred platform but, I do own a few games on origin. I own about 155 games on steam (20% of them have been played) and 5 games on origin (battlefields and titanfalls).
On Steam.. 75 I think. I don't like throwing money at my screen but some games are a must have. If you were to include Blizzard games or Runescape for example it could go up to probably 90. That seems reasonable.
1,175 on Steam; 15 on Origin; 2 or 3 on Battlenet, I forget. And a couple of CD cases of PC games I've been hanging on to for probably 10+ years.. original Elder Scrolls: Oblivion, The Sims 1 and 2 with the expansions CDs, those old Dogz/Catz games that literally no one I know played but me. Probably 40-50 games sitting in those cases.