First bike. Need something I can work on myself.

[Jimbo62]

Just my 2 cents here,
I started on an '82 Honda CB550 that I pulled out of a barn.  Put tires, chain and sprocket, rebuilt carbs, cleaned it up, and rode the piss out of it for the first year.  Taught myself to ride on an old bike.  Then upgraded to a '99 Kawasaki ZX-9R, like going from a golf cart to a dragster.  But... that's what I wanted.  So... I now ride a Connie 2011 and love it.  Have been through the dual sport thing during some years and don't argue that this could have been a great way for me to start, but in hind sight, the older bike and then a newer bike is for sure the way to go.  
I am now getting the wife into riding and have just picked up an '82 yamaha virago with 14,000 on it.  I test rode it, and though very old, it's whipped just enough to feel like that old 550 I started on.  Easy to work on, tons of parts on ebay, easy to resell next spring, crusier styling, and just big enough to not get bored on.  I'm 6'5" and 230lbs and it felt small, but for someone your size, an older virago might just be the way to go.  I am very mechaniclly inclined, so this was not a factor, but I have not heard of them having too many problems.  By the way, I picked it up for $1500 and plan on selling it for the same amount next year, no matter how many miles she decides to put on it.
Hope this helps,  Jim
PS kawasaki vulcan 750 is another choice in this class, and my brother started out on a Suzuki 800 that looked like a fatboy.  He loves it and has no reason to have started smaller and no desire to go bigger.  
PPS let us all know as soon as you buy something, we would like to know what direction you took.

[jsanford]

K75 BMWs are good bikes.  So are the pre-2001 BMW F650s (and lowered ones cost even less). Freeway-capable but with a good temperment.  I did some work on mine without knowing much about motorcycles, thanks to the highly-comprehensive FAQs on the Chain Gang and three-disk instructional video series available as a free torrent.

The only suggestion in this thread I disagree with is the Monster. Mine has a little too much "whee!" factor, the stock suspension is lacking if you're over 150 pounds and I've seen few on the used market that have been regularly ridden and well cared for.  States vary, but it's my smallest displacement bike (except for the 2-stroke Kaw) and after four years is STILL the most expensive one to insure.

[fossil]

FWIW, any inline twin (EX500) or 4 (Bandit, Nighthawk, GPz) are great bikes to learn the basics with. I started on an 85 GPz550 and wish I still had the pup...

[25knots]

+1 for the GS 500.  Take my advice, based on all of six months of motorcycling experience, with many grains of salt, but I've found this bike to be super simple to work on.  Take the gas tank off and the engine top end is right there for you to work on without much trouble.  

Aside from some bad congealed gas fouling the fuel system somewhere (fixed with a $4 carb/injector degunking solution from the gas station) I haven't had single problem with the bike.  The gas clog was likely my fault too, as I left the bike sitting for about a month without treating the gas beforehand.  

As for whether or not a 500 will keep you entertained, I'm a little less confident.  I'm already starting to want something more powerful, especially after riding my friend's liter bike this past weekend.  But overall a 500 will do anything you want it too.  I did a week long tour with my brother this past summer (Blueridge, Deals Gap, Cherahola, the works) and I never had a problem keeping up with his Tiger 800.  I had about 40 pounds of gear strapped to the passenger seat and the bike never had any problem in the twisties.    

Anyways, have fun bike hunting.  What you get won't be perfect, not much is, but you'll love it anyway.

[25knots]

I should also add the bike mechanic friend of mine recommended the Ninja 500 over the GS 500 for three reasons:

1) The Ninja's got more horsepower
2) The suspension is better
3) In his opinion, the Ninja looks cooler

He's probably right on all those points.  The GS 500's suspension seems a bit loose, but I don't have much to compare it too.  On the other hand, the Ninja's good looks come from the faring which is not always such a good think to have on a first bike.  The only other substantive difference is that the Ninja's engine is liquid cooled, which adds a bit more mechanical complexity, though probably not too much for a beginning mechanic to figure out.