Yes most Tibetans would agree that it is HH Dalai Lama, as he represents the Tibetan people. You will find that Tibetans of all lineages will be very quick to say this, though with Westerners, they might be less inclined to agree. This is in many cases because for non-Tibetans, what the Dalai Lama represents as the figurehead of Tibet is not something they identify with so much. Still, many Buddhists from all the lineages who have been around 10 years or longer have taken empowerments and teachings from His Holiness, so they see him as an important source of inspiration, if not the main one.
Traditionally the "pyramid" of the stature of the various lamas went something like this, according to the political structure: Dalai Lama, Panchen Lama, Sakya Trizin, Karmapa, Ganden Tripa. Though of course for Karma Kagyus this position of the Karmapa would be supreme in importance, as their lineage really is built around the incarnations of the Karmapa. Most serious Karma Kagyu practitioners practice a Guru Yoga associated with one of the Karmapas (Karma Pakshi, 16th Karmapa etc) and recite "Karmapa Khyenno" as the Guru Yoga component of their ngondro.
The Nyingma tradition is less institutional than the others so it is not until exile that there was an appointed "throne holder" for the entire tradition, though now that there is I am sure that position would figure somewhere in the pyramid as well.
The role of His Holiness the Dalai Lama has become even more crucial in the present day, when the Tibetans have been scattered across the earth, as he serves as a beacon of unity and hope for the Tibetan people. I pray that he lives long and continues his beneficial activities for beings.
In order to ensure my mind never comes under the power of the self-cherishing attitude,
I must obtain control over my own mind.
Therefore, amongst all empowerments, the empowerment that gives me control over my mind is the best,
and I have received the most profound empowerment with this teaching.
brtsal ba'i bkhra drin