Check out TV's late night talk shows and you'll see two different breeds of Arien Rams.  After all, we all are more than our Sun Signs!
Like most Aries, Dave and Conan dominate the conversation as they repeatedly butt-in and inject their personal opinions. With intense, rapid-fire gestures and inextinguishable enthusiasm, they push "the comedic envelope" to the outer edges.  The dynamics prove quite entertaining!  
Notably, both sport crowned horns of hair -- which constantly jump out of place.  The reddish coloring in their hair and complexion enhances the fiery Aries qualities.

	Ascendants: Taurus & Virgo

Both of these "hosts with the most" have a earthy ascendant to subdue the raging fires.
When his solar torch isn't on full blast (and he isn't reacting to others), Dave locks into his Taurus personae-- taking on a staid and bull-headed presence. Positively, this grounds him down and makes him appear more contented and relaxed. This Venus- ruled ascendant also adds a leisurely charm to his personality.

Our first impression of Conan is quite different. He often appears jittery and nervous. When he began his show, he constantly pulled at his tie and he twitched restlessly in his chair. The image makers went to work but they couldn't change his Virgo ascendant. He's still nervously fusses over the details-- especially when his Aries sun is not in control.

	Moons: Capricorn & Aquarius

These night owls have different "reactive qualities" and consequently, different emotional natures and senses of humor. 
Dave's Capricorn lunacy is sarcastic and cynical -- sometimes seemingly cruel.  In these saturnine moments, his face takes on a hard, chiselled, goat-like appearance.  With such rigid emotions, he diligently maintains order and rarely lets others take control of the show.

On the other hand, Conan's show seems more "free spirited".   His "out-of-the-blue" responses make his interactions with his guests quirky, intriguing and subject to erratic surprises.  This lunar position also makes him optimistic, friendly and it adds a light and airy quality to his personality.  Uranus on his ascendant enhances these Aquarian qualities, but it proves too far out for most tastes.