Some good users are Quickseller, Vod, actmyname, jackg, nullius (with expert-like postings) and theymos of course.
Quickseller hasn't earned a huge amount of merit, and most of what he says is completely hypocritical anyway. I take everything he says with an enormous grain of NaCl.
Nullius made some excellent posts, but he's currently not active on the forum.
Theymos got a bunch of ass-kissing merits, and I suspect that's exactly why he's gotten so many merits.
I agree that Vod, actmyname, and jackg consistently make excellent posts, as do most of the members with tons of merit
Anyone can be a Copper Member if they pay the fee. There really isn't anything special about that title.
Instead of trying to read posts of highly-merited members, I would suggest using the ignore button more often, and be selective about which sections you're reading and posting in. If you're trying to read good posts in Altcoin Discussion, good luck with that. You won't find anything good there, nor will highly-merited members be posting there. Most of the good posts get made in the technical sections and in Meta/Reputation. Sad, but true.