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;
Elrond - Starts with the best unmodified mage rank in the game but also has Vilya (+50 Mage) artefact for good measure. He easily has the beating of all the DS characters in a personal challenge.
Cirdan - Another Noldo character. He starts with a +10 Mage artefact and +20 command artefact. The Noldo have great characters overall, but these two are probably the best.
Murazor - The Witch King is in a bit of trouble at game start! He needs good characters and Murazor is certainly good. He has the best DS mage rank (with Urzahil) and also has stealth. Murazor has some top notch artefacts at game start as well - a +30 mage artefact, a +10 Command artefact and a couple of combat artefacts.
Urzahil - Starts with three of the best artefacts in the game. The Ring of Iron Magic (+30 Mage), the Cloak of the Dark Abyss (+40 Stealth) and The Voice of the Dark Tower (+20 Emissary). These complement his already excellent abilities. Unless your name is Elrond your not going to come out of a personal challenge with Urzahil intact!
Khamul - The Dragon Lord tends to get a bit of a battering at game start, and this position tends to be eliminated quite frequently. Nonetheless, Khamul is a top notch character capable of being a superb mage and thanks to his stealth a top notch agent as well. The +30 Mage artefact helps!
Glorfindel - It's a Noldo character again (did I say they had good characters?) and Glorfindel is an excellent commander/mage. If the Noldo raise an army it's usually Glorfindel who leads them into battle. Glorfindel starts with a couple of combat artefacts and a +15 Mage artefact.
Ji Indur - The Lord of the Clouds. His starting stats aren't that great, but give this character the Ring of Wind and Cloak of Dark Abyss and he can assassinate anyone. This name strikes fear into the hearts of the Free peoples! Many players favourite character he usually tops the kill charts and his timely assassinations can be more valuable than an army of 10000HI.
Gothmog - The Dark Lts Warlord. The best unmodified command rank in the game. Commanders become less effective as the game wears on but a 70 commander at game start is useful for the Dark Lts in threatening away undefended North Gondor pop centres. He also starts with a couple of nifty artefacts which make him all the more dangerous.
Tarandor - The North Gondor equivalent of Gothmog. If anything, Tarandor is more dangerous than Gothmog because he starts with two good command artefacts pushing his command rank around 100.
Everyone has their favourites, Bain, Thranduil, Akhorahil, Dendra Dwar, Celedhring, Angamaite, Argeleb and Din Ohtar are notable others. However, I think the 8 names above are the best characters in the game. If you claim the scalp of these then your doing a good job!