I usually go for an OldBlood geared up for destroying units. The big problem I had was loosing to static combat res of ranks + outnumbering, so I usually go with the following build;
Mobile flanker:
War Drum, Sword of Might, Maiming Shield, Talisman of Protection
The Drum allows you to march right past the enemy and bring the charge into their flank. 5 S6, 1 S5, and 4 S7 attacks in the side, should get most units fleeing. Frenzy then kicks in, and you should now be nicely lined up at the flank of the enemy's main battle line, catching them between your Carnosaur and your own battle line. The other advantage to getting your terror causer to the flank of the battle line is any failed terror tests will cause fleeing units through straight their own battle line, rather than to the back of the table, causing more panic tests. Carnage.
The weapon choice can be tailored depending on the army you're facing; +1 Strength (my normal choice), +1 Attack, or -2 AS and Flaming.