OK, you can tell by my handle that I'm a little biased on the subject

but, objectively speaking I believe the G17 to be the best first(or only) pistol to buy. (Caveat, if anyone is reading this form a free territory with CCW the G19 is the way to go

)
They are competitively priced, dirt cheap when you consider reliability. As has been stated before, accessories like lights, upgraded sights, holsters ect are plentiful. They're very easy to maintain, yes they still need to be cleaned.
If you're not a shooter you can go ahead and accessorize the heck out of it too, with everything from a 3.5lb trigger to a steel frame and gawdy graphics. If you actually shoot your gun though, you're better off spending that money on training and ammo, it doesn't need improving.
People say they aren't attractively designed, aesthetics should have no bearing on one's choice of a pistol though. If it goes bang everytime I pull the trigger, it's beautiful to me.
Save your money and go with the plain, fixed sight, model. The night sights are OK, but there are much better after market options. -COUGH- XS 24/7 BIGDOTS -COUGH- Stay away from adjustable sights, they are for people who can't shoot a pistol.