Loud and clear tend to be at odds with one another, at least dependant upon your idea of what loud is. Some just want to get loud with some conventional components, in which many will get loud. Others think that loud consists of compression drivers (horns) and high efficiency midrange drivers.
That said, I feel the king of midrange drivers goes to SEAS with their Lotus/Excel drivers. As far as clarity and detail, I haven't experienced anything that can touch them when comparing apples to apples. The best part is they aren't harsh and resonant, though they are detailed to the point of being nearly surgical in their reproduction, bringing out everything in your music (including flaws). I know I'm pretty set on them as a "best driver, but they're pretty much singled out in the true "rigid" driver category. There are few high end manufacturers that choose to do a true rigid cone driver, and it paid off. Vifa has some fiberglass mids like the MGs and the wood fiber XTs, but they're somewhere in the middle of the rigidity/damping compromise and really don't excel anywhere. A lot of the Focal drivers are a damping/rigidity compromise with their composite cones, but they tend to have some of the negative characteristics of both damped drivers and rigid drivers (though to a lesser degree), though they do sound good when implemented well, they take some tuning to get them to sound natural.
If I felt like a warmer sounding driver, I'd go for Scan-speak Revelators. They'd be better for smoothing out music that isn't so well recorded, yet they're still very detailed and clear.
I'd say out of the components I've personally heard/dealt with, my top 5 would be (not in any particular order, just numbered to keep track):
1. SEAS Lotus Reference- IMO, the best 7" midbass driver out there in the car audio world. Exceptional resolution of fine detail and neutral midrange. The metal dome tweeter is shockingly smooth and very detailed.
2. Rainbow Platinum - Excellent midrange clarity combined with powerful, punchy midbass output. That is paired with what I feel to be the best compact dome car audio tweeter. It's a set that has what you like about Focal, except that the Platinums have improved midrange clarity and the absence of a tweeter that sounds like banging trash cans together .
3. Dynaudio 360 or 240 Esotar (take your pick) 360 has a powerful 8" midbass, an incredibly clear and natural sounding midrange, with an excellent, smooth tweeter. Very neutral set that gains points for image stability when the drivers are installed well. The Esotar tweeter is one of the best large format tweets out there, 7" midbass has a silky midrange that's easy to listen to.
4. AVI Tri-star BSM - Best "out of the box" component system-I mean that as in it having one of the better passive crossovers available and not being really quirky as far as tuning. Very smooth and detailed sound to them.
5. Morel Elate 9 3 ways - See reference to Dyns above, except they are a bit more "ballsy". That 9" midbass driver hammers
Honorable mention would be the DLS Iridiums, but they really don't shine until you run them active and focus on tuning the rather quirky midrange driver. If you can tune it, they are very flexible install-wise and one of the better sets because of their imaging capability. If you have a processor, you can basically put the midbass flat in a door, pop the midrange in a kick panel, and tweeter in pillars and get good results without a huge amount of attention to aiming drivers.
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