Definitely 17 inch and definitely HD Screen
Hey I own two MacBookPros,
and have a apartment mate that has a 15 inch MBP as well. Well while he was initially quite smug that I would regret my decision to get the 17, after over a year of use, the opposite is in fact the case. do no get me wrong the 15s are great machines. But it was the consensus in my apartment (and both of us have extensive technical and creative uses on laptops) that the 17 was a clear winner. It seems to dissipate heat better having a bit more room to pack in all that tech, and as a matter of fact, the 17s have the lowest number of manufacturing defects as well.
I mentioned I owned two macbook pros, well I decided to basically let my lady co-opt my first intel MBP 17 (a top of the line 2.33 MBP) so I could have an excuse to get a new top of the line 2.6 gighrtz, 200 gigabyte 7500 rpm, with 4 gigabytes of ram, and a high definition screen. I mention my new hot rod only because I have been shocked at how much I have enjoyed and found useful the highdef screen option of the new MPB. when using the same apps as my lady (both content creators) she has on occasion found it necessary to teasingly complain that she cannot fit the tool configuration that "I have" and therefore I need to buy yet another new computer (Not gonna happen). And that is even though we both have access to second screens to hook into. Why because in those many instances when you can and want to keep your focus on one LCD at a time, its really nice to be able to set it up as you would your typical 20 inch LCD display, which is the essential gained ability via the extra pixels on the screen. But lastly, and on a more frivolous note, this new screen seems just so much richer and nicer than I remember my other display ever being even when new. (Its not fair to compare the MBP screen that has had the heck used out of it for I guess 2 years, as there is a natural LCD screen fatigue). Also If you really want to do things up proud I recommend you get yourself a desktop only "archive" 2 terabyte drive, a 23 or a 30 inch display, a wireless keyboard and mouse, and lastly some rough and ready external drive that you take with you as a large and completely backed up 1 terabyte drive full of things you want to have that you do not want filling up your internal drive. Now all this assumes that you really have a need to use a MacbookPro and have some substantial funds. but my point here that even with an external display and some nice big hard drives, I am glad I went 17, the higher speed disk, and the HD drive. in particular the 17 and the HD screen. because even when I away from home, I can plug in my larger hard drive via 800 firewire, and turn on my lap top and boom, I have a powerful desktop on wheels. If you have the money to go all the way on the macbook pro and make a nice income and are truly worries about having a really portable machine, then I say, get the 17HD MBP and then cough up another 1,200.00 dollars for a regular macbook, then you have it all. I know a number of people who have done that that are doing very well and want to have a smaller lap top that for the basics. I mean you can get an air too if you want, but for my money, I would not pay that much more for a machine with to few I/O options and is of yet a very very new idea which could eventually be massively revised or eventually orphaned. but the MBAir is different matter entirely.
My final thought on this way to long response is I am sure will be very happy with any of the Pro books, but if this is going to be your main machine, and you are into the digital lifestyle enough to call this laptop, your "centerpiece machine" then I can tell you both the 17 and the higher res screen are worthy upgrades that you will greatly enjoy. And will in fact make a measurable difference in your overall satisfaction. And before the MBP I have not been a huge laptop fan, as in the past I felt they were always over prices and under-delivered and often had gotchas of one sort of another, especially if it was going to made your main machine.
Enjoy, and I would be interested to hear with what you decide and how you like it.
andy