Ok, Western Generals seem to get of a bad rap here. Yes, the German generals were impressive, but were they really the be all and end all?
Plus, I don't think Air Commanders should count really...
1. Slim - built the Forgotten Army from nothing, able to get along with Stillwell and Chiang Kai-Shek, victorious against Japanese, loved by all under his command
2. O'Connor - led the assault on the Italians and could have finished them off, captured, escaped (not generalship, but pretty cool), went on to command in Normandy
3. Horrocks- Fine divisional commander in North Africa, and impressive corps commander in Normandy handling XXX Corps. Loved and respected by all who served with him.
4. Brooke - Speaks for itself I think.
5. Wavell - (What? Asks everyone...) Yes, oversaw the almost total destruction of the Italians in North Africa. Would have succeeded had it not been for Churchill's meddling. Did a fine job as penultimate Viceroy of India.
Honourable mention:
Simonds - Truly impressive handling of the 1st Canadian Army in Normandy. Fine Divisional officer as well