In my opinion, the two sets I would personally run on him would be a variation of the DD and Rock Polish set depending on what fits better on my team. A DD set would allow Tyrantrum to outspeed base 130's after a boost which is a crucial benchmark as many of you have noticed. This leaves him to be out run only by scarfers, Mega Manetric if that becomes thing, and the two base 150 megas, Mega Aerodactyl and Mega Alakazam. As long as you can get rid of those, this set packs more of a punch than the Rock Polish set. Here is what I would use:
Tyrantrum @ Life Orb
4HP/252Atk/252Spe
Item: Life Orb
Ability: Rock Head(Assuming he gets it)
Jolly Nature
Dragon Dance
Head Smash
Dragon Claw
Earthquake
DD is obvious for the boost to speed which is crucial and the attack boosts makes him even more deadly. Head Smash becomes an absurdly powerful STAB while Dragon Claw can be used to kill dragons or when you don't want to risk a Head Smash miss. In addition Head Smash lets Tyrantrum get pass most Fairy types except those with Steel Typing such as Klefki and Mawile(both who fear EQ). It is interesting to note that Head Smash beats both Skarmory and Togekiss, something Garchomp cannot do with out being walled by the other(Stone Edge can beat Togekiss but not Scarmory while FireFang/FireBlast beat Skarmory but not Togekiss). Lastly Earthquake seems to be his best coverage move when not using Strong Jaw since it has the ability to beat out many steel types as significantly damage Aegislash without suffering the -2 from King's Shield.
On the other hand, a Rock Polish set can be used similarly with the added benefit of bypassing several scarfers at the cost of power making Tyrantrum a great late game sweeper. As someone mentioned this allows him to outspeed up to 111 base speed scarfers.
Tyrantrum @ Life Orb
4HP/252Atk/252Spe
Item: Life Orb
Ability: Rock Head
Jolly Nature
Rock Polish
Head Smash
Dragon Claw
Earthquake
Although the Strong Jaw sets on him look appealing and are by no means bad, I think passing up a recoiless Rock Head is not worth having essentially STAB on biting moves. Head Smash on a Strong Jaw set coupled with LO will make Tyrantrum take huge amounts of damage just from recoil which is why I am really hoping he gets Rock Head. Tyrantrum seems to be looking like a really nice Pokemon to use this gen, but in an OU setting he seems to have a very big enemy, Scizor. It doesn't matter how many DD or RP you get under you belt, Scizor will always be a pain for Tyrantrum especially the CB sets which and OHKO him. I see great offensive synergy between Tyrantrum and Magnezone more so than any other previous Dragon types. Although defensively they share two weaknesses, Magnezone's steel trapping abilities not only get rid of steels not weak to Earthquake such as Ferrothorn and Skarmory, but also discourage Scizor to not lock himself into Bullet Punch from fear of getting trapped and killed with HP Fire. (It is also important to note that although their defensive synergy is not the best, Tyrantrum is 4x resistant to fire which helps with Magnezone's fire weakness).
