Bike size.  Yes, everyone wants bigger, badder, did I say bigger?  First a note to the young man who wants to start with Harley larger than Sportster: 1)its not a women's-only Harley, ask many of our female bloggers and they will tell you so.  2)you know they're heavy, even the lightest big twin weighs in at 650-700lbs, depending on accessories. (My 1200 Sporty is around 570 and the Superglide with accessories probably hits around that 700lb mark-fun to manuveor in a tight area with a lean on the concrete). 3)if you've had some experience in riding and still want the big twin,  for the lowest cost, try a Superglide, or if leg reach is a problem and you don't mind a few thou more, Try a standard Softail or Low Rider.
For the rest of you. Unless you just want that big horsepower or you're a long distance cruiser, I'd consider a smaller bike.
Here's my thoughts on this.  1)If you're just putting around town, a few miles to work or the store, campus commutes, etc, I believe that a Scooter or small displacement bike will serve you well. So unless you're really tall or overweight, and you're never go over 50mph, anything upto a 500 will suffice (a 500 Vulcan carries my 270-280lbs quite well, even at 70mph-heck, evem a 250 Ninja carried my butt at that speed).
2)Mixed riding.  Mostly in town, but an occaisional weekend trip, etc, a 500-900cc will do just fine,  The smaller size for in-town use with plenty of power to carry you farther distances (the 500 Vulcan also carried my 180lb nephew from North GA to Panama, FL and back-only hitch-a battery cable came loose...the 883 I had at the time covered me with a packed duffle bag there and back with power to spare and still had 50+ mpg, the Kaw was over 60mpg!)  3)Some local, but a lot of weekenders.  If just to make it easier on the engine to carry your luggage, anywhere from a 750 to 1200cc is just fine.  Of course, if you 2up or find that most American companies don't make an upper mid range size bike, you have got that big twin.
I've learned that bigger is not always better.  Since most of my riding is in town, I've found that a good mid range size bike is best for my purposes.  I've had many bikes in my time including a CB360, GL500 (Honda), more recently an 883, Superglide Twin Cam, 700 Yamaha Maxim, and 1200 Low.  Also have riding a 500 Daytona and 650 Bonneville, 750 Norton Commando, CB 750 Custom, etc.  The 700 Maxim was a very nimble bike and luckily, had great brakes, but I guess I had gotten used to the low rpm feel of the Harley so I sold it and got the 1200Low.  I wish I had stuck with the 883.  For me, the gear ratios worked better for me for in town use than the 1200 does (wider ratio).  When I traded in the 883 for the Superglide,  my father and I would take any day off as an excuse for a long ride or a short trip to the next town(s) so I thought thr larger bike would be better for the ride and fairly nimble enough for town use.  But as his health declined and the rides did not come as often, I found the Glide (with hardcase saddlebags, shield , etc) to be cumbersome on many of the roads I took and an awful lot of bike for a 7 mile trip to work at no more tha 55 mph (if I exceded the 45 mph limit).  Well, at his passing I inherited the Superglide back (he took it over as I used his stripped down Glide as a trade in for the 1200) and am now putting the 2006 1200 Low up for sale and after the sale will be looking for a smaller bike for local commutes and saving the big 'un for the weekend ride (whenever I can get one-weekends are hard to find these days in this 24/7 world).
Okay, a lot said and a bit outside of the general subject, but I hoped it helped those thinking they need to get that BIG bike that it doesn't always need to be big.  If shorter rides or care more about mpg, stay in a mid-size to a smaller large bike. If you want more power, don't care as much about mpg or want compfort for that long haul, well then...go big!.  As far a those short commutes, etc, yes Virginia, you can go a bit smaller.
By the way, what ever happened to those great starter bikes like the 350 to 500?  They were great to learn on and still had enough power to get you through for many years (only Kawa has a 500 these days-that I know of).  I remember my father taking weekly 200 mile commutes from Jax, Fl to Tampa and back on a lowly CB350 Honda for his job for quite a while (back before they dropped the speed limit down to 55) and bike never complained.  I rode a CB200 30 miles one way to work and 30 back for a while on the expressway with out a problem.  Probably would have enjoyed the ride more with a larger bike (as I did when I got the GL500), but it got me where I need to go with no problem and good mpg to match.  Many riders I've met lately have downsized or parked their big cruisers and pick up 500 to 750cc rides to save gas and wonder why they ever went for the two-wheeled land yacht.  For those who kept they're big bikes, they say they only use them for those big road trips anymore.

'nuf said...bigger not always better.
Thanks for the time you took to read this.


The house is always rockin' with Stevie Ray in the stereo.    

I have a 04 Star, 1100 V-star classic. After doing some intake mods (DIY pods) and changing the pipes. I added at least ten more horses and get 46 MPG. I feel I can do everything with this bike that a larger one will do. That includes 2up, long distance with luggage. It's also fantastic to ride around town or over to the next town and back with just me on it.

Thanks, 2steps.