Mirror Coat only effects special attacks. Counter is the one for physicals, and with maxed attack Poliwrath one-hits everything with a counter move (nullifying the counter). Destiny Bond only goes first if you're faster, and if I just ate a salac berry that's very unlikely. The only thing that would survive a hit from that Poliwrath that has counter is Wobbufett, and he's banned from competitive play as an uber.

Another extremely powerful Pokemon now that Diamond and Pearl has separated Special and Physical attacks for all types is Gengar. STAB Shadow Ball will kill anything in 1 hit without godly special defense, Psychic and Thunderbolt cover remaining types very well. Hypnosis is a decent backup (though a gamble at only 60% acc.).

If you want RAW physical power, nothing beats Choice Band Tyranitar.  Choice Band doubles your attack but limits you to only one move (until you switch out).  With enough speed EVs Tyranitar will oustpeed all the medium speed Pokemon and has enough defense to avoid an OHKO from anything but a powerful fighting move, but with Crunch, Earthquake, Stone Edge, and Pursuit will OHKO pretty much everything in the game with ease.  That said, he probably won't live forever, and the fact that he brews up sandstorms can be trouble unless you have a team built around sandstorm (in which case it's a great strategy). 

I thought Destiny Bond always goes first, my bad. A Rhyperior / Slaking / Lucario might be able to endure the hit.

Feraligator FTW! Water beats rock and fire. Ice beats grass, Earthquake slaughters electric.

If you want RAW physical power, almost nothing beats Choice Band Tyranitar. Choice Band doubles your attack but limits you to only one move (until you switch out). With enough speed EVs Tyranitar will oustpeed all the medium speed Pokemon and has enough defense to avoid an OHKO from anything but a powerful fighting move, but with Crunch, Earthquake, Stone Edge, and Pursuit will OHKO pretty much everything in the game with ease. That said, he probably won't live forever, and the fact that he brews up sandstorms can be trouble unless you have a team built around sandstorm (in which case it's a great strategy).

Other than mewtwo, a normal type pokemon known as ditto, level 100 would rape.

If you mean the strongest Pokemon by combined stats then Arceus is the strongest legendary and Slaking is the strongest non legendary.

Blastoise ! fear the canons ! Give him hydro pump, fissure, blizzard, and icebeam .

FAIL

MAGIKARP



FTW!!