Teancum, our girl is a pitbull/rhodie mix. Rhodies are some of the damndest dogs out there. They're so dang smart, and lovable, and awesome.
If you have a chance to own one, I highly recommend it.
Oh, and for the record, Golden Doodles are GREAT dogs (never met a labradoodle, so I can't attest to their intelligence or lack thereof). They suck at "guarding" anything, but they are so sweet, and so pretty, and SMART as a whip (comes from the poodle side, I think). And they don't shed (er... most of them don't). We met a full sized Golden Doodle last time we were out in Havesu. I'd drop $2000 on a dog like that one any day of the week. They're not as "foofy" as you might think. The one we met was HUGE, and quiet, and just an all around great dog. They almost look like a mix between an irish wolfhound and something with silky soft hair. Beautiful animals.
Anybody who has owned a poodle will attest to their intelligence. I'd own a poodle in a heartbeat (though I'd prefer a standard size over the itty bitty ones).
I'd never own a lab again. They've got about half a brain and that's it (or at least, that was the case with the 3 I've owned over the years).
I LOVE pit bulls. They have the most personality of any purebred dog I've ever met, and as others have mentioned, they're downright intimidating when they need to be, regardless of their size.
I really really like Alaskan Malamutes, but you've gotta be prepared for the shedding. My old girl (Charlie) used to shed sweaterfulls of fur every year in late spring. It was miserable. Of course.... if you're good at that sort of thing, you could harvest their fur for spinning into yarn.
I love mastiffs for the same reason that I love pit bulls. Only problem is that they are heart breakers (IMO). They don't live long enough. I don't think I could handle losing my sweet mutt every 6 or 7 years.
And then there's my hubby's favorite dog breeds:
Border Collie - smart as a whip, not so great at being a ferocious guard dog, though.
Viszla - fantastic hunting dog, wouldn't know how to be mean if their life depended on it and has no undercoat, so needs to be inside.
Rhodesian Ridgeback - great all around guard dog and family dog.
Springer Spaniel - Fantastic little mutt for everything from cuddling to hunting. Not so good for guarding.
Hell... I guess we just love dogs.