Sure thing. So a few notes, you can host CS:GO and Dota 2 games on lan. You do have to be logged in to steam and have a network connection, but the games themselves can be played on lan, so the outbound connection doesn't have to be fast.
As for some other games, I highly recommend a cracked version of the original WC3:FT, Starcraft, Battlefield 1942 and Vietnam.
Some more insane people, start up a 3-day game of Civilization or Heroes of Might and Magic 3.
If you have enough people, I also recommend Enemy Territory (2003 version) with some mods, its awesome. But you need at least 20 people for this.
Just for laughs, if we end up with a tie, our tiebreaker is Liero behind a single keyboard.
Edit: Oh, forgot about Age of Empires 2, Rise of Nations. But if you want a good Lan-only experience you kind of have to use cracked versions of old games. I make up for this morally by buying a newer version if there is one even available, then use a cracked old version for playing.
Hell even online multiplayer games are waning, there's just nothing good anymore that isn't "free to play" and every game is desperately trying to create its own ecosystem to "make it big".
The last decent one I played was among us, and that was only during the pandemic. Simple gameplay, no dlc, accounts, microtransactions (at that point at least).
Now when I have people over we just break out a ps1/xbox/360...
Edit: Oh, forgot about Age of Empires 2, Rise of Nations. But if you want a good Lan-only experience you kind of have to use cracked versions of old games. I make up for this morally by buying a newer version if there is one even available, then use a cracked old version for playing.