Ive already been dark elves and im looking for a rounded good army but i cant decide between high elves, wood elves, bretonnians or dwarfs.
If you like dark elves then you should like wood elves and high elves. Just tell us what kind of armies do you like? and how you play your dark elves? what fluff intrests you most?
Dwarfs: Completely the opposite of Dark Elves. Hard in defence, slow attacking, tough. Rely heavily on war machines and stationary ranged attack either to soften the enemy up while the slow-moving regiments close, or to soften the enemy up while they approach.
Background wise they are a solid, dependable and honourable people, who keep their word, etc.
If you're after a total change from what you're used to, go with Dwarfs. Utterly, utterly different.
Wood Elves: Similar in some ways to their Druchii cousins, Wood Elves have some very nifty and significicant differences. THey are capable of being tougher and harder in battle, with the option to take large swathes of forest spirits- treekin, treemen and dryads are all (compared to elves) exceptionally tough in combat. They are a more fluid army than any of your other options, requiring a very unusual playing style and not lending themselves well to a frontal assault. Dark Elves don't lend themselves well to a frontal assault either, so you may be used to that.
Background of the Asrai is unusual. No longer the prancy happy tree-huggers of old, they are now more akin to the original Germanic faery tales- cruel, capricious and definately very nasty, without the actual "I'm going to drink your soul!" evil of the dark elves.
If you're after a change but not a severely dramatic one, wood elves should accomodate your somewhat. Particularly if you're sick of painting elven skin- their is very little skin on the Asrai models, and with the amount of Forest Spirits in the army, you'll be painting a lot of wooden colours.
High Elves: Having neither played with nor against High Elves, I can't really comment on these guys much. They can play very similarly to Dark Elves, with a smooth selection of heavy cavalry (Dragon Princes) light cavalry (Ellyrion Reavers) and the standard (to you at least) backup of spears and archers.
Their background is pretty much the other side of the coin compared to the Dark Elves you love, but I wouldn't really call them good guys. They're not terribly fond of dwarves and they have little else but contempt for the races of men.
I'd go with High Elves if you like the idea of a twisted mirrior of your dark elves. It'd be fun to design the armies to face each other, then get a friend to play one side or the other to get him in the hobby. You could make a high elf army the Unsundered cousins of the Dark Elves, with personal vendettas and vengeances, painted in a similar style. The High Elves with a similar crest- the family before the Fall, etc. Could be lots of fun.
Bretonnians: Bretonnians are like the knights of Arthurian legend that have been inked heavily in black ink. They are a hard-hitting heavy cavalry army that relies on brute force to do their tasks. There is a wide scope of various tactics, and you cannot neglect your infantry, which you will need to mop up enemy survivors. They play very differently from Dark Elves, being less reliable (LD value is usually lower) and more expendable. Although, not terribly expendable.
Their background is, as I said above, Arthurian legend with a wash of black ink. They claim to be all noble and high-falutin', but treat their peasants like crap. The fact that each knight has unique heraldry will make the army time consuming, but very rewarding to paint.
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That's it. Personally, I'd recommend the Wood Elves, but that's 'cause my girlfriend is starting to collect them and the miniatures are very very nice. It took ages for them to be released, but they are pretty. Combined with their very flexible army design and nifty, darkish background, they're a lot of fun. And they're still elves, so you won't need to alter your usual tactics too much, at least at first.