I have spent way too much time on this one. I think that ultimately I cannot recommend any of the current offerings. The apple 24" looks amazing but the contrast ratio is pretty poor and makes it hard to see blacks from grey. Good calibration can help, and switching to a higher gamma opens this up, but at the end of the day you're still crushing colors and designing for a gamma that nobody else uses.
The apple 30" is not a great reference monitor due to backlight unevenness, but it seems like this problem has gotten better over the 5 year run they have made with these things. I should mention that macrumors is saying there is a pro 27" display coming through shortly. The high price for these is the biggest downside.
An interesting consumer entry that only costs around $200 is the Dell SP2309W that has a whopping 2048 x 1152. This monitor got great reviews and cnet chose it as its top pick for monitors 23-24". It also has a wacky stand that lets it fold down to a completely flat 180 degree position on a desk. The bad news is that its TN. And really, who needs a wider screen for C4d? 1920x1200 is probably a better resolution. The higher end IPS dell monitors in the $500-$700 range should be excellent. I used one of the IPS ones last year on a job and it was great.
There are a few LED backlit monitors coming to market from LG, Samsung, etc but for the most part they are built on TN panels. Among these are the LG W2486L and Samsung XL2370. The samsung is quite impossibly thin which makes it a very appealing display. These are not professional grade monitors but they are cheap, and LED backlights seem less flickery to my eye. CCFL backlights have a flicker frequency meaning that the light discharge that we see is actually a very rapid on again off again. Think of it as being similar to the flickery Fluorescent bulbs that are in office buildings. LED backlights similarly use a rectifier to do the same thing, but to my eye have significantly less - or even NO discernible flicker. Anyway, these cheap LED backlight displays are cheap for a reason. The bigger a TN display is, worse the problems with off-axis viewing. This is simply because you have to turn your head a bit to see the corners of the display, and this increases the index angle between your eye and the display. Despite this, these displays are not a bad choice, especially as an interim monitor. I have seen them go refurbished for under $200. If you think you can deal with 1920x1080 they are not a bad way to go.
Lastly, Sun Microsystems makes what I believe is the most ergonomic monitor there is. Its S-PVA 1920x1200 which I believe are an excellent compromise panel. See link here: http://lcd24-7.info/Monitor/Sun/24.1-LCD-Monitor-v4/Default.aspx I own the predecessor to this model, and I like it enough to buy another when it comes time. So whats wrong with it? Well purists will say that IPS is a necessity. Its also CCFL backlit. But, I can say from experience that Sun stuff lasts a lifetime and its scrutinized to a higher level of quality than just about any other manufacturer including apple.
So, the current problem with the LCD market is that there is a lack of LED backlit IPS/SPVA displays. Apple understands that these two qualities go well together. Unfortunately they have taken it upon themselves to make every mac display look like an iPhone. Suffice it to say, I am highly annoyed with this fact. Its called a monitor for a reason. I want to monitor actual contrast, not iPhone colors. The actual color gamut on the thing is spectacular, I don't understand why they would ruin this with a consumer level contrast ratio. So, until other manufacturers start investing in LED backlighting for high end IPS monitors the pickings will be pretty slim.