Like I said, we're too damned nice.

There is being nice, and there is being afraid of a confrontation. This sounds like the sort of situation that needs to be addressed and soon. It only takes one guy to ruin it and as soon as people start dropping out because they don't have fun when That Guy is "playing" you might lose your game night. You don't know if he is already costing the shop business. I have stores I never want to because of their resident asshole's reputation.

I would talk to the management and let them know that something needs to be done. Also stop allowing him to cheat. Insist on seeing cards, and if that doesn't work just do the same thing back. Have fun with it. Compete with your friends to see who can be more outrageous in their antics with him. Get those tiny clear dice with the white lips, roll fast and claim all sizes. Don't bring an army list and change your warhead to exactly what you need.

All of this has been said before, but to reiterate:

Try talking with the guy outside a game one-on-one. Just a nice friendly chat: "Hey, that's a nice shirt, where did you get it? Are you cheating, by the way? Because if you are I need to get me some tar and pluck a chicken. I'm going to grab some coffee, want some?" Something like that.

If that doesn't change this guy's behaviour and if he just refuses to acknowledge the fact that he's being an ass. Call him out on it during a game again. Not willing to show his hand? No. Show them now or the game stops and will not start again until this guy's away from the table. Don't just let the guy brush you of. Be sure to have the rest of the group back up whoever is doing the calling out instead of them meekly cowering under the table.
If you're really too goshdarn friendly to do this, then find someone in your group who isn't this timid. Being friendly is one thing, but this is your fun we're talking about. Step up to defend it!

Public shaming usually works really well to either force someone to change, or just to get rid of them. Yeah, it's a dick move and not a nice thing to do. True. But he is ruining the fun of everyone at the table and he isn't a friend of you or anyone you're friends with.

If this guy still just acts like nothing is wrong, then you've pretty much exhausted every option outside of violence. Time to get the whoever is in charge of the shop involved. If the guy in charge starts bitching about you refusing to play with someone tell him this guy was cheating and generally not being fun.
If the guy in charge still bitches then give him the simple choice between this one guy vs. you and the rest of your group (again, be sure everyone in the group is on the same wavelength on this).

Yeah ... I was reading a thread on RPG.net about bad gaming experiences and almost every one of them boiled down to a "we were too chicken-shit to confront the creep and just suffered in silence until the situation became so over-the-top intolerable that Zombie-Hitler wouldn't have taken it any more." [I'm paraphrasing.] This saddens me, partly because I'm just as guilty as anyone else of this same crap. I've sat in pretty terrible game groups with jackass GM's for nearly two (2) years before eventually leaving and finding a couple of great game groups to play with. Even then, I was "nice" about it by sending a conciliatory email thanking him for his effort and explaining that I wouldn't be playing anymore. That didn't get me a damn thing, by the way, as he never acknowledged the email nor has anyone I gamed with ever contacted me. They apparently think I'm the dick for leaving.

For what it's worth, I feel your pain. Take it from someone who's put up with too much shit for too long, it's not worth it. Others have advocated speaking to this person in private and if that doesn't help, then approaching the store owner. Those are very reasonable suggestions, and at least you can feel good about yourself for having tried to do something about the situation.

Or, you can hunker down and save up the bitters and end up writing an hilarious post in some future RPG.net thread on "gaming with that guy!"

So you'll call a guy out on the internet over grammar but you won't confront someone in person who is cheating you and your friends?

You don't have to look anyone in the eye over the internet.

And there's about a zero chance of getting slapped in the face. Besides, this place is full of Good People. That Guy? I don't know how the fuck he'd react, because I don't really know him and I can't read people worth shit. He might be reasonable, or he might haul off and start trying to shove my teeth through the back of my neck.

That would be very funny.

Besides hiding his cards, and not paying attention to rules, does he act like a freak?