I agree, it would have been way more helpful to the readers here if he'd included that info, because it makes all the difference when you're recommending an exchange.  It would also help to know which country OP is in, though I'd understand if he didn't want to disclose that info.

I think Binance is still king these days, though I haven't used them in months, not since they reorganized their US service and excluded a bunch of states.  But whether you're trading altcoins or just bitcoin, they're probably the best overall--and one of the most trusted, too.  Kucoin would get my "next best" vote if Binance isn't an option.

If you're just looking to buy bitcoin with fiat, Coinbase would probably be a good option if they're available in your country.  I'd advise staying away from the lesser-known exchanges altogether and sticking to the bigger, more well-known ones.  There have been so many scam exchanges, hacks, and everything else that you have to be really careful.