I vote for Jesse Ventura's voice as the best. I think his voice is the main reason he won the governorship of MN. Leslie Nielsen and Steven Wright have underrated voices as well. But JEJ is definitely top-ten.
Back to JEJ... (this one from the "who cares?!?" dept.)
Once David Letterman had a top ten list of phrases that sound funny when spoken by James Earl Jones, then JEJ came out to read the list. Can't remember most of them, but one was "Neo-Synephrine".
Here's the list... (from CBS' Late Show Archives)
Top Ten Words That Sound Great When Spoken by James Earl Jones
10. Mellifluous
9. Verisimilitude
8. Guppy
7. Stolichnaya
6. Boutros-Boutros Ghali
5. Neo-Synephrine
4. Pinhead
3. Mujibur and Sirajul
2. Heebie-Jeebies
1. Oprah