I went with the lion because doh Lioness, then it turns out it has a mane, sigh. Also it has the ability to fear sort of. If i could choose a new one i would go with fox or wolf. Yeah i will probably do a ranged rogue next playthrough just to see, but i am guessing sneak attack with bow makes it much stronger than ranger is currently. Still there are always ways to tweak your character in these games to make you come out on top so not to worried. Ranger is still awesome.
Heh, thats why I created several rangers to check them all out
Then ended with a wolf, because wolves are cool.
Agree about tweaking, there are just so many ways you can develop them. My only issue was with assigning stats, because I always want to have the most conversation options. My first ranger was a total disaster. 
Pets are a bit unreliable. But if you are going to rely on it to do damage then it is prudent you either hire or recruit a fighter to tank/cc.
A party of rangers is actually kind of fun. Watching enemy paladins trying to swat a horde of boars and stags is amusing.
I'm trying to make a tank out of Eder, but its a bit hard since they are premade with certain stats and abilities. Im not a fan of soulless hirelings, dont play with them.