There's more info we need to make solid recommendations.
-What's your budget?
-What kind of switch do you want? Rat-tail style trigger, thumb switch on the side of the grinder or paddle switch?
-Do you want one that can use cutoff wheels and grinding wheels? They can't all technically use both.
-Do you want variable speed?
If you want cheap, the HF models have good reviews. If you search for a coupon you can find certain models as low as $9.99. Also well-reviewed are the Black and Decker and cheaper Porter-Cable, Hitachi and others.
If you want a paddle switch, then I personally like the Makita paddle switches the best.
If you want adjustable speed, then your choices are a lot smaller. I recently bought the Kawasaki adjustable speed grinder from Tractor Supply. Normally, I wouldn't buy a Kawasaki grinder, but it was the easiest way for me to get adjustable speed. Kawasaki grinders are just Chinese grinders sold by Alltrade Tools, which licenses the Kawasaki name to use on power tools.
Metabo may be the "best," but it will probably be way overkill for the OP's needs and not the best use of his dollars.