Below is a (long) list of all the starting characters in ME1650. However, probably the top starting characters (and most likely best in the whole game) are;
Saruman the White - Everyone wants to play the White Wizard. Saruman starts with the best Mage rank in the game, (as you would expect) and being a neutral has time to improve that rank even more by spending time gathering powerful artefacts.
Elrond - Powerful in the 1650 scenario, powerful in this scenario. Elrond is an excellent emissary but it's his mage rank that is impressive. Elrond starts with an array of powerful artefacts that makes him formidable in challenge. I've even heard that later in the game, he can be used to eliminate Dragons.
Murazor - The Witch King still has holdings in Angmar in this scenario so he needs good characters if he wants to try and hold them. Murazor is certainly good. He has the best DS mage rank (with Urzahil) and also has stealth. The selection of artefacts he has at game start help as well!
Galadriel - A new character to the 2950 scenario and she's quiet good! Possibly the best character in the game, a match for anyone, you don't want to go up in challenge with this elf unless you are holding some powerful artefacts. Claim her scalp and there will be lamentation in Lorien and a blow to your opponents morale.
Ji Indur - The Lord of the Clouds. His starting stats aren't that great, but right from the start if you give this character the Ring of Wind and Cloak of Dark Abyss and he can assassinate anyone. It's not because of who he is, it's what he represents. The figurehead of the Dark Servant side. If you're controlling a free nation and you kill this guy, then you're team must be doing well.