[Morthoron]

Halbarad
Elrohir
Elladan
Thirty extras to be Dunedain Rangers

Actually, I could come up with only three actual speaking parts (and the extras) that I think would be necessary to save The Two Towers movie from Peter Jackson's inane need to juxtapose his immense ego (and poor scripting) onto the original plot.

I have the three extended movies, and overall I think the movie trilogy was fine, but I really never cared as much for TTT, most likely because of Jackson's heavy-handed rewriting of Tolkien. By adding the Dunedain Rangers (with the sons of Elrond) you eliminate:

1) Aragorn being portrayed as an undecided and lonesome loser. The movie made it seem like he hadn't a friend or kin in the world (save for the Elves), when at the time of the War of the Ring he was the longstanding Chieftain of the Dunedain.

2) Aragorn frenching his horse. Eliminate the whole Warg attack scene where Aragorn falls of a cliff, floats down a river and hugs his horsie. That's fifteen minutes of film time that could've been better used elsewhere.

3) The Elves coming to Helm's Deep. Sorry, it was a silly plot twist. And what happened to all the Elves after the battle? Did they all die? They just disappeared. Equally silly. If Jackson wished to emend the original plot, then have the sons of Elrond and the Dunedain coming to fight at Helm's Deep. I don't believe the impact would have been lessened.

4) Elrond appearing magically in Rohan, having ridden hundreds of miles through enemy held territory just to drop off a sword? Maybe he should have led the Fellowship, as it appears he had an easier time getting through.

With the addition of Elrohir, Elladan and the Dunedain, one gets a commitment from Elrond and the Elves without sending a spurious army of Elves (again travelling easily through enemy territory). In addition, one gets a sense of Aragorn's stature and history, and seeing the grim Dunedain would have been far more interesting than the proliferation of blonde elves Jackson had a penchant for.