Right now, I am using the Raidmax Agusta. This case was kind of the catalyst to get me wanting to design one because it showed me so many things that I like while also having some glaring problems that I think no case should ever have.
Here's a link in case you don't know the case:
http://www.newegg.com/Product/Product.aspx?Item=N82E16811156284
Keep in mind that most things are subjective to personal taste as well as specific needs.
Pros:
1.I love gawdy, flamboyant, flashy hardware. The angular, boxy look as well as door on the front, LED, etc, is a look I've always loved in a computer.
2.The number and location of CD drive bays are very functional. You could design a build in a number of ways around them. Tool-less design is always nice.
3.Good, well positioned USB access on top as well as build in fan/LED control.
4.The bottom chamber that holds all the SSDs/HDDs and has it's own air flow is a great design, both functionally (in theory, see below for downside) and aesthetically.
5.Plenty of fan spaces for great airflow (there's actually a downside to this, said below)
6.This case is amazing for watercooling*
Cons:
1.Getting the back plate on this case while doing cable management is... absolutely... terrible... Why, why, WHY is almost every case I see made with a backplate that hugs the case where all the wires are????
2.This case has negative air pressure by default, meaning dust collects on the backside and any other significant opening. There's little to do to fix this because...
3.The power and SATA cable routing to the bottom channel that holds the storage is placed at a terrible spot, right over where a drive would be. And the backside of the channel doesn't have enough room (just like the backplate...) meaning you have to route cables very intuitively. If you have a completely modular PSU where you don't have SATA power connections every few inches on a single strip, this is less of an issue since you aren't trying to cramp 4-6 inches of wire between connections in a 1.5 inch gap between drives.
4.The construction is a little flimsy as it is covered in several places in plastic.
5.This case it typically negative pressured
6.This case is at the same time terrible for water cooling*
*I have put a CD drive and a multi-card reader in the top 2 of 3 CD bays and put a pump+res in the bottom two bays. I then routed tubing from there to the GPU, then to the outside of the case where I ghetto mounted a small, 80mm rad to the back of the storage chamber, making use of the airflow the case already had and not having to buy any new fans. The tubing then goes back in to the pump+res. I could add another rad on the intake fan in the front, aiding GPU cooling but making CPU cooling a bit worse. The top of the case is designed in an odd way where you couldn't fit a rad with fans on it while using an aftermarket air CPU cooler unless it was low profile. I assume the case was designed with a standard CPU water cooling kit in mind. if I were desperate, I could put a 140mm rad on the exhaust port in the back. That would aid GPU cooling and help make the case more positive pressure by impeding exhaust.
For an example of another case I like but still have issues with, see the Azza GT1 and ask if you are curious what I like about said case.
Thoughts, comments? Again, anybody who knows a fully custom case maker, say so!