Are you wanting to use the built in sv.db SQLite that is included in Gmod?
Or do you want something that you can tie into a website like MySQL?
Well I would like to use the sv.db, because all I really need to do is store money (scores), ...and I don't feel like I need an online scoreboard.
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But it really depends on what is better, I need to store players scores, perks, and inventory items.