I don't subscribe to the "smaller displacement" theory for new riders - I've been riding dirt bikes (started with a KX80) since 1983ish; street bikes since about 1990ish. My first street bike was a Hurricane 1000, and I've had liter bikes ever since (YZF1000, R1, CBR900, etc).
I've only been without a bike for the past 2 years or so (travel too much to justify keeping one around)....
Anyway, I'd say that your bike choice should be based upon a few things:
1) What style of bike do you like?
a) Cruiser
b) Cafe/retro
c) Sport
d) Touring
e) Dual Purpose
f) Harley-style
2) What will you use your bike for?
a) Sunday rides/Boulevard cruising (short trips)
b) Sport riding
c) Track days/spirited riding
d) Touring; longer rides
e) Passenger on board often
3) What's your budget?
a) < $3,000
b) $3,000 - $5,000
c) $5,000 - $7,000
d) $7,000 - $10,000
e) > $10,000
4) What's your size?
a) < 5'8"
b) 5'8" - 6'0"
c) > 6'0"
2wheels hit the nail on the head with the cruiser being a little tiring to ride for any amount of distance; you'll take a beating from wind (cruisers usually have no/small windshields), and the outstretched riding position gets a little tiring as well.
Sport bikes/Sport touring bikes are great for just about any type of riding except for around town riding; the fairings are designed so that the wind helps support some of the load that's placed on your wrists/frontal body. I rode my YZF1000 from DC to Madison in a single day (930 miles) without much drama.
Dual purpose bikes are fun if you have off-road environments available to you, but for the most part, I don't enjoy them too much.
Oh, before I end this rambling post....back to the displacement thing - people who are new riders buy a smaller bike because they think it's more safe. Therein lies the problem - at first, they're deathly afraid of the throttle and treat it like it's canned nuculear explosives.
Then, as they get used to the bike, they start to flog it a bit more and that's when they end up in trouble - they think "well, this is only a tiny little 600cc; I can handle it!" and with that, they come in to a corner too hot, lock up the rear brake and go for a little slide-slide.
With a larger displacement bike, you're more apt to respect the throttle for a longer period of time, and are less likely to become over confident and cocky. Just my own personal theory, which I developed from watching many friends crash their new 600's while other friends kept riding their new 1000's.
The Suzuki Bandit or even the SV650 (I know, lower displacement, but this is an exception) might be great first bikes.
Whatever your choice, I'm sure you'll enjoy it!