best general team?

I don't think there's a definitive answer to that. Thing is, the units are balanced reasonably well, and many generals have a lot niches that is great for some people but not really useful for others. It all comes down to playstyle, but here's some suggestions assuming a F2P 8 man team:

Cavalry/Artillery Focus:

Murat - Dabrowski - Lan - Ney - Massena/Karl - Mahmud II - Alexander I - Nelson/Sakurako

My preferred way to go. Ney is the cheapest guy on this team who's available right from the get go, so he's probably the first one you get. Then you can fill the spots as you want. I'd personally wait until Crimean war before getting Nelson/Sakurako though, so you could fit in a 2nd inf or 3rd art gen until then.

Infantry/Artillery Focus: 

Massena - Karl - Barclay  -Suvorov - Murat - Mahmud II - Alexander I - Nelson/Sakurako

Not my preferred way to go. I personally don't really like infantry, but there's a lot of people here who swear by their musketeers, so I guess there's some merit to them. Anyway, this is the best team I can imagine for an infantry/artillery focused squad. Massena is the cheapest guy here so get him first. The same thing applies to all admirals, wait until you get to Crimean war.

Artillery/Cavalry Focus:

Mahmud II - Alexander I - John - Scharnhorst - Murat - Dabrowski - Massena/Karl - Nelson/Sakurako

I don't know about this one. The main weakness that artillery generals have is that all artillery units except Rocket Artillery have a crippling -25% damage to ALL land units, and Rocket artillery unfortunately costs 220 gold and a mind-blowing 10 population to maintain. I haven't seen anyone try this either. And the same thing applies to all admi... You get what I mean.

Artillery/Infantry Focus:

Mahmud II - Alexander I - John - Scharnhorst - Murat - Massena - Karl - Nelson/Sakurako

This is siege town. 

Balanced Aura:

Murat - Dabrowski - Massena - Karl - Mahmud II - Alexander I - Nelson - Sakurako

Kind of a dubious team imo, particularily two admirals. I guess this is an simple path to go if you're unfamiliar with everything and haven't found your playstyle. Get Massena first.

Best team in the game:

Clinton - Prevost - Merveldt - Brown - Belsford - Verhuell - Duckworth - Falsen

Best team in the game, I think you'll average 60 damage across the board.

Also here's some really weird to fit generals:

Bismarck/Garibaldi These guys can siege like no one else. Bismarck has the highest consistent siege damage due to the combination of plain fighting, assault, tunnel, and high stats. While Garibaldi has the highest siege damage outright due to Mountain fighting, assault, tunnel, and attacking twice roughly 1/5 of the time. The problem is that that's pretty much the only things they're amazing at.

Sophia She can deal almost as much damage as Napoleon. The problem is that you lose her palace ability, one of which is the best in the game, if you hire her.

Davout/Paget Tactic master cavalries. 20% of the times they can hit harder than even Murat in a turn. Quite a few people like Davout since he's tougher, but Paget is really similar to him except he's slightly frailer.

I'll probably recommend going for a balanced team before you decide for yourself how you want to play.