Spanish are a good civilization but not great, they have a lot of royal guard units, such as the pikeman, lancer and rodelro, also having Crossbowmen, Musketeers and Skirmishers is a big help, their explorer can create his own war dogs and you get the most support from your home city, Spanish are essentially for the beginners and the weaker players.
The British are a very unique civilization, their manor houses spawn settlers when built and they have very good longbowmen which fire at a rapid rate from a very long distance, however they are expensive, rockets are also unique for the British, they fire overa long distance with an explosive landing and believe me, they hurt when you get hit. British is for those of you who think pounding away at someone for along time is a good tactic.
The French are one of the best civilizations in the game, if not the best mainly because of their settlers, for an extra 20 food your settlers can double up as weak infantry and build, collect resources and fight so much better than regular settlers, but that's not all with the French. They also have the best cavalry in the game, Curassiers, they then upgrade to Gendarmes which are fantastically powerful but at a hefty cost!!! Not only that the French can get 2 forts and are best at allying with native tribes, whew that's a lot!
Personally I don't think much of the Portugese except thefact they get a new town centre in every age for free when they upgrade and an explorer's spyglass which reveals unexplorer territory, also they have a very strong navy and the best dragoons (anti-cavalry cavalry) in the game. Their unique infantry isn't bad either but it's not really that good, Cassadors, just Musketeers with a different name.
The Dutch are a very good civilization becuase of one thing, banks! These banks produce coin constantly and pretty fast therefore you wouldn't need any settlers on coin, but because of this you are limited to 50 settlers, to make things even better settlers cost coin not food, the Dutch have an average range of units and can be amazing, if used correctly!
The German are a fantastic civilization to be if you've had the game for a while and are prepared to adopt new and weird tactics to try and get things to work. First of all, the German settlers are normal however they also have special unique settler wagons, which cost 2 population, but are worth it! They gather and build at least twice as fast as settlers and have a lot more HP, you can get these from your home cities, age upgrades and, with a home city shipment enabling this, buy them from your mill for 100 food, 100 wood, however you are only limited to 20. Next we go onto the German infantry, to say it like it is, their Doppelsoldners are the best infantry in the game, their siege attack, with all arsenal upgrades and home city shipments is 142! The Imperial Gendarmes for France, with the same upgrades, only have a siege attack of 60! Basically the siege attack enables a lot more powerful attacks thatn you'd usually get, for example a group of 20 fully upgraded Imperial Doppelsoldners can destroy a fortified outpost with 1 hit each, that's how effective they are. The German's also have Crossbowmen, Pikemen and, as the manual says, one of their best units, the Skirmisher, this is indeed their royal guard. Now we come to cavalry and, if you've seen the best cavalry page Uhlans, german unique cavalry, are 3rd, so they must be pretty good as well, and cheap only 150 resources for 1, that's half the Curassier! They are good, in the fact you don't ahve to buy them but will be destroyed quite easily, even at imperial level, by anti-cavalry. The German also have anti-cavalry of their own, the War-Wagon, this is a wagon with a gun on the front, which has good range, good attack and good HP, all around a good unit. Along with all these fantastic units the German also are equipped with Imperial Cannon, which is talked about in the best artilery page and all the other artilery you would expect to have, but they lack grenadiers, but, lets face it, who need them with all these units?
Then we come down to Ottoman, in my opinion the best, but hardest to control and undersatnd in the game. The Ottoman settlers cost absolutely nothing and come out constantly through the town centre, there are a few upgrades from the mosque which let you get more settlers and to make them produce faster. However this is not the Ottoman's best feature, they're unique infantry, janissaries are very cheap, this lets you buy lots very early on, therefore you can attack very early on and win games in less than 10 minutes, not joking, because i've done it, twice. the Ottoman have more unique units than any other civilization, one of these is the Great Bombard. This cannon is at least twice the size of an ordinary cannon and twice the fire power, at their imperial state they can destroy an outpost in 1 hit! They have the best artililery in the game and can get it in age 2, for all these reasons, i give the ottoman's my best civilization award!