BADxCARMA

1) Window.  I think everyone wants to see their PC's guts these days. :P And for good reason; so much good work is put into component design these days.  Motherboards and video cards and fans and coolers didn't look nearly this good five years ago.
 
2) 2 USB 3.0, 2 USB 2.0, headphone, and microphone.  It's the standard, it's what people expect.  Fan controllers are meh; I personally don't want to flip a switch every time I fire up a game or something.
 
3) Basically any modern case is set up for good airflow, even the $40 cheapos.  I mean, with the ATX standard there aren't many different ways to do airflow.  Things get a bit freaky with Mini-ITX, but that's a much less common formfactor anyway (though small formfactor builds are becoming very popular very quickly).  Ironically, though, really really high-end cases aren't necessarily the best for airflow as they're designed exclusively for water cooling.  But those really high-end cases are so big anyway that airflow doesn't even matter at that point. :lol:
 
4) Bottom.  Top mounted PSUs are UGLY. :lol: And bottom-mounted allows the coolest air to be drawn into the PSU, since heat rises (though it probably doesn't make all that much of a difference).
 
5) Cable management is all about having enough room behind the motherboard tray.  Older cases have either very little room behind the mobo tray to fit cables (gotta have room for that fat 24-pin), or, in really old cheapo/ancient cases (and pre-builts, ugh), have literally zero space behind the motherboard tray, so your cables just end up everywhere and blocking everything.  Pretty much any case you'd buy today though has great cable management.
 
6) Design-wise, my favorite is probably my own case, the CM Storm Enforcer. :P I also like the NZXT Phantom 630 and the Corsair 600T.  I like a design that's somewhat aggressive, but still smooth and elegant.  In terms of functionality, my favorite is the Corsair 350D, a MicroATX case that holds more hardware than a lot of ATX mid-towers.  Beastly little case.

1. I prefer things that look slick and clean, but at the same time are curvy rather than in the shape of a box. NZXT Phantom (the original) is a good example. It's the case I own now.2. 2 USB 3.0 2 USB 2.0 Fan Controller is nice and a bonus but not necessary.
3. The NZXT Phantom is not a good example of this. It has crossflow (where air goes through one side panel out the other) and that's horrible for the design. Any case with a fan mount in the center that's adjustable is good for this.
4. Always bottom. Top makes the case top heavy, and is ugly. The only good thing about it is that the 4-pin and 24-pin reach easily.
5. Any case with plenty of grommeted holes and zip tie points. Having a special section in between the HDD cage and the motherboard for routing is a bonus.
6. NZXT Original Phantom. It's the aesthetics that won me over. Anything on the inside can be modded to be functional, but imo it's much harder to make something aesthetically pleasing than it is to simply make it "functional". Both is easier though.

If you're looking for the best of the best when it comes to the sleeved cables, the best option would be to sleeve them yourself. But who wants to spend the time and frustration on that?
 
The 2nd best alternative (in my honest opinion) would be the corsair individually sleeved kits. They come in a small array of colors to match your build and are interchangeable with other corsair PSUs. Not to mention the quality of the cables is ASTONISHING. Pick up a corsair ax760i and a cable kit. You will not be disappointed.
 
The 3rd best option (if you like red) would be the EVGA super nova series PSUs. The quality is similar to, but a bit worse, than that of the corsair kits but without the extra cost of buying them separately. One thing though, they only come in red. But I think there is a model that has black or its mixed.
 
For sleeved cables, those are the only options I would recommend unless you have a case with a TON of cable management. Then you can get Bitfenix alchemy extensions.
 
These you can get for ANY PSU and are individually sleeved extensions. But you need a lot of space to tuck away the excess cables and that takes time and not many cases can accommodate a full set of extensions. But, you wouldn't need to buy a fully modular PSU. A word of warning though, buying extensions for all the cables adds up the cost immensely.