To the point of owning a game twice, there isn't much I can do. I know I will be selling this for a loss. I cannot link the account because Valve would close my account and I would lose my games. That is why I am doing this under the table. Some games include...
Player Unknown Battlegrounds
Tomb Raider Collection (Includes the Tomb Raider Remake)
Splinter Cell series
Fallout 3, New Vegas, 4
...and plenty of others. My account is old, so there are perks in that. My roomate wants it for $50. That is somewhat low especially considering PUBG is worth a hardset $30. I was looking for a couple hundred, maybe $2 a game. That would be about $540. Definitely a good deal, but more risky than selling to my roomate.
It's definitely my fault, when I first got Steam, I was seeing games that were usually price $50+ at discount maybe $20 and I kept buying them without playing.