Audio is very subjective, so if possible, I would suggest you go to a car audio retailer that carries multiple brands/lines and have a listen.
Personally, I have always found Infinity Reference series to have a balanced sound, and didn't have any fail on me in the several vehicles in which I've had them installed. I might just be convincing myself of this, but textile/"silk dome" tweeters sound smooth and pleasant to me, whereas "titanium"-type tweeters sound harsh. The latter aren't bad if you're into stuff like EDM where you really want sharp highs, but I don't like them for vocals.
The new Infinity Reference speakers deliver accurate sound thanks to edge-driven textile tweeters for smooth highs, and patented Plus One™ woofers that deliver surprising bass output.
www.infinityspeakers.com