I have the Milwaukee M18 grinder and it is great especially with their 49-94-4500 stainless cutting wheels.  I do commercial steel and aluminum door work and use mine all the time...GREAT tool. 

Metabo should be the first and last on your list.

Angle grinders are their core business and second to none. The cordless version isn't as fully featured as their corded ones, but even with the autobalancer, it's one of the smoothest angle grinders I've used. Made in Germany.


Bonus is their brushless drill is also really good so you can share batteries, and they started manufacturing tools for Mafell too in case you want them in red.

Makita, love mine use it all the time. They have a brushless one out now.

thanks for all the responses.  i had not mentioned in the original post that my two finalists were metabo and milwaukee in that order because i did not want to skew the suggestions and i was also interested to see if there were any other options that i had not heard about.  i have and heavily use a number of corded grinders:  metabo, milwaukee and makita.  while they all have held up, i do prefer the little extras on the metabo i have like the variable speed control and the general feel of the tool.  i also purchased recently a metabo combi hammer drill which i absolutely love and selected it even over the hilti.

yesterday, when i stopped in at my local fastenal where i got my corded metabo some years back they did not have any cordless on the shelf but i could not help but notice that there was a stack of german made metabo grinders in color boxes and right next to them in a black and white box was a chinese made metabo, so i think that currently they are made in several places.  that seems to be the case for proxxon as well.  earlier tools i have from them are from germany or lichtenstein, but the most recent two things i got from them are from china, so we shall see if they hold up in time.

yesterday, when i stopped in at my local fastenal where i got my corded metabo some years back they did not have any cordless on the shelf but i could not help but notice that there was a stack of german made metabo grinders in color boxes and right next to them in a black and white box was a chinese made metabo, so i think that currently they are made in several places.  that seems to be the case for proxxon as well.  earlier tools i have from them are from germany or lichtenstein, but the most recent two things i got from them are from china, so we shall see if they hold up in time.

Their lowest end corded grinder is made in China I believe, along with some of their other non-core tools (so far, my cordless recip saw and cordless circ saw are made in China). The drills and cordless angle grinders are all made in Germany I believe. There's some other forum where a member was keeping track of all the COOs, I'll see if I can find it again.