Would be interesting to see what opinions people have formed based on the given nationality of players. Could also be useful for quick reads at the table if we seem to have a consensus.
I'll start it off...
Swedish
In general Swedes tend to be overly tricky and aggressive and fall in love with suited connectors. Bad swedish players are among my favorite opponents because they will call or raise big bets oop with draws and bluff a lot attempting to "outplay" you. The average bad swedish player is probably among the worst players overall. The good ones however are probably among the best and most difficult ones to play.
Most likely to go all-in with a draw
Irish
Haven't played with that many, but the ones I have noticed have been downright retarded and many of the worst plays I have ever seen have been from Irishmen. Pushing preflop with K3o, or calling an all-in with a T high flush draw on a paired board, things like that.
Most likely to be drawing dead
Americans
More than other nationalities I find americans seem to bring their ego to the table. Getting outplayed, losing to a suckout or being bluffed off a hand seem to matter more than losing money. Many Americans take the role of "sheriff".
Most likely to call you down with middle pair
French
Seem to love suited cards and are generally loose/passive chasers, with a few bluffs thrown in. Rarely valuebets marginal hands and often pushing their big hands.
Most likely to slowroll you on the river