The two Pokemon fighting... Steel, Psychic and Electric!
Metagross, before looking at the arguments. Psychic, there we go.
The word "quadragonal" is the only word with "dragon" in it where "dragon" is not a root word. That makes it awesome.
Magnezone is in that group of turrrrrible Gen 4 evolutions of Gen 1 pokes that didn't need them (Magmortar, Rhyperior, etc.)
So, Metagross by a mile.
Metagross, simply because its design looks cool.
Metagross would kill Magnezone with Earthquake. It also looks better. Magneton looks better than Magnezone too, but Metagross is the coolest.
Why's this even a question? Metagross wipes the floor with Magnezone fifteen ways 'till next Sunday.
SoulSilver FC: 1334-2716-6164
Platinum FC: 1591-7683-8872
Easily Metagross, in usefulness and appearance.
I prefer Magnezone just cause I stragize with it more. But Metagross more cause its a beast for me in the Battle Factory.
URPG STATS----> http://bmgf.bulbagarden.net/f401/trainercaseys-stats-59492/
Metagross is destined to beat Magnezone when it was seen that the latter had a speed drop that makes it slower than the former, and not to mention Metagross has a powerful movepool including Earthquake, AND added to the fact that Metagross is a pseudo-legendary, you have a very biased match-up. The only thing Magnezone has going for is his ability to trap Metagross and his great Special Attack, which is the bane for many Steels because this is usually their least strongest stat that is exploitable (honourable victims include Aggron, Skarmory, Scizor (no Earthquake), Forretress and Empoleon (weak to Electric)).
Anyhow, I like Magnezone better because of his UFO-motif (better design in layman's term).
Metagross! It is wicked awesome and a touch cooler than Magnezone.
Credit to HikaruIzumi for the awesome avatar!