i'm not really a fan of fords of holdens, but if i had to pick one, ford would probably be it.
commodore's (let's leave the fully imported astras, vectras, etc. out of this) are not advanced cars, and until the latest commodore came out with the new engines they had been using very old engines from GM.
negative comments from commodore fans about how V8s are the only performance engine are of course going to be biased. ford engines moved away from push rods have had DOHCs for quite a while now (i don't know exactly how long, but obviously longer than holden), and they compete well with the larger and more basic holden engines.
but then again, we're all biased. a lot of people here think that skylines are the best car on the planet i think skylines were one of the best japanese performance cars when they were in production, and the R32, 33 and 34 models still compete with the best today, but they aren't the best car on the planet.