Xel'naga Caverns is a map where both players are really close so they can play aggresivly in order to win the match. By other hand, second expansion is relatively safe and the third one needs to destroy destructible rocks. There are also two xel'naga towers in the middle of the map.
Here doesn't exists close positions so they only can appear cross position or mirror position. There are also two Xel'naga Towers in the middle of the map and lot of destructible rocks so it's a funny and balanced map.
Typhon Peaks is a map where is hard to defend second expansion but not the first one. There are also two Xel'naga towers in the middle of the map. This is a good map because there are other ways to go if the opponent is in the middle of the map.
Slag Pits is one of the newest ladder maps in battlenet. There is only one Xel'naga tower and only two destructible rocks on gold mines.