Well, the problem with the PS5 is that most of the really good PS5 games are also PS4 games. I'm sure there's a difference if you have the right TV setup, but...I'm not sure I could personally notice the difference myself.
Elden Ring us probably the biggest game right now. It's a Souls game, but most people have had a easier time getting into this one than others.
Horizon Forbidden West is another big open world game. I personally like the artstyle on this one more than Elden Ring, myself.
Astro's Playroom already got mentioned, if you like platformers.
Ratchet and Clank Rift Apart is probably one of the best games out, and it's PS5 exclusive.
Returnal gets pretty good reviews. Might want to check out a few reviews first, to see if it's for you, though.
Deathloop is a unique first person shooter featuring time travel.
Kena Bridge of Spirits is also on PS4, but worth taking a look at.
Ghostwire Tokyo might be worth looking into, if you want more action games.
Death's Door might be something to look into, if you want something a little more indie.
Sackboys Big Adventure is a good platformer.
It Takes Two is a really good co-op game...but you can ONLY play it co-op.
Ghost of Tsushima Director's Cut is a good game, if you haven't already played it yet.
Stranger of Paradise Final Fantasy Origins...might be worth looking into. It's probably not as big of a disaster as some thought when the first trailer came out.
Guardians of the Galaxy might not be the most amazing game, but it's probably a solid time if you really like the characters already.
Spider-Man Miles Morales is another good game...but it might depend on if you've already played PS4 Spider-Man.
Godfall is...not actually all that great. But...that art style is oh so very pretty. If you can find it cheap, it might be a fun enough time?
As for upcoming games, there's: God of War Ragnarok, Stray, Forspoken, Spider-Man 2, Hogwarts Legacy, Sonic Frontiers, the Star Wars Knights of the Old Republic Remake, and Final Fantasy 16. (Some of these are definitely "wait and see" titles, but worth knowing about)