New here, don't want to ruffle any feathers. But as to the greatest mech of all time, I appreciate your need to consider some lesser known candidates, and some mechs that have great style and character, but there is only one choice, which everyone in their heart of hearts knows is the greatest mech ever designed, the mech which embodies all the characteristics of a true mech in the mechiest way imaginable. The mech of mechs, the mech which was implied at the inception of the very conception of the concept of mech and until its manufacture, all mechs were, despite their fine qualities, mere prototypes. I speak of course of the Atlas, and particularly of the AS7-D. I hate to be forced to state the obvious. All the other mechs mentioned are nice mechs in their own way. But, seriously...Cmon!
Unfortunately, that is still subjective. The Atlas doesn't go much in the way of speed or long range combat, unfortunately. It might embody Mechwarrior as it does to you, but others may hold another opinion. If we are talking a general mix of jack-of-all trades designs, the good 'ol Timber Wolf takes the prize. However, we all have personal preferences, and varying views of the "norm". That is exactly what this thread is for, finding the best of the best