This ended up being longer than I intended, sorry for the verbosity.
I have a 2002 Prius, and I love my car. We first heard about them when they were taking pre-orders for the 2000, and would have ordered it then except that a) it didn’t have cruise control yet, and b) I wanted to wait until they’d had a model-year or two to shake the bugs out. I ordered mine last August and picked it up in January. I absolutely love it, have I said that already?
Reliability: I’ve only had mine for six months so I can’t say how it’s going to do over the long term, but we have had only one incident in those six months, and that was our fault: we let it get too low on gas, and it shut down. I’m due for my six-month maintenance check any day now, which is covered by the dealership.
Extra or special maintenance: Not by you, the owner. The batteries do not require external charging, as they are recharged when you brake or coast, or when the engine is producing more torque than it needs to power the car. The dealership strongly recommends that you take it back to them for service, as it’s still a relatively new thing on the market and Tony’s Garage might not know how to safely deal with the electrical system. (They also told me that whenever they work on a Prius - even if it’s just changing the oil - they wear rubber suits to ground themselves. I don’t know if I believe that.)
General driving experience: It’s really not that different from a regular car. You don’t have to change your driving habits at all, although if you want to maximize your mileage there are a few tricks you pick up. The car can accelerate up to highway speeds right along with the rest of the crowd, and I’ve driven it over 80 without feeling like I was pushing it too hard.
One of the neat things it frequently does is shut down the engine/motor completely when you’re stopped at a light. This doesn’t waste power idling, and it starts up right away when you touch the gas again. I have a friend who got really freaked out by this though - he thought my car was stalling.
The car has plenty of headroom and can seat four adults comfortably. It doesn’t have power seats and it doesn’t have trunk access from the back seat (it can’t - the battery compartment is in the way) but those are the only two things I wish it did come with.
You don’t have to think at all about whether to use the gas engine or the electric motor, because the Hybrid System does all that for you and automatically adjusts things. It really only has three gears: Drive, Reverse, and Engine Braking. It does as much as it can with the electric motor and uses the gas engine as an assist when you’re accelerating or driving at highway speeds.
Insurance rates: I’ve got State Farm and they didn’t seem any higher or lower than usual for a new car. I just got my statement and can’t remember the numbers offhand, but if you really want to know, you can email me and I’ll look it up.
Independant garage: I haven’t looked, because the dealership’s going to do all my servicing free for the first couple years, and I figure I’ll just take it to them.
Other stuff: It’s got a counter that keeps track of your cumulative MPG since the last time you reset it. The best MPG I’ve gotten so far is 44.8 over 800 or so miles. I accidently reset it the other day, and I’m almost back up to that - 43.4 for 45 miles. The 800 was mostly surface street driving and some freeway commuting.
Be prepared for people to want to look at it and ride in it. I’ve had a lot of people ask to look under the hood. There’s a big silver boxlike thing in there that says “Toyota Hybrid System” that I tell them is the Flux Capacitator. Or the Main Deflector Array, depending on the crowd.
Do not let it run out of gas. It’s not designed to run on the electric motor alone, and if you do run out of gas, it will give you just enough power to let you coast to a safe place, and then once you shut it off it won’t let you turn it back on. You get all these big warning symbols flashing on the screen. It does warn you when you are low on fuel, and usually gives you adequate notice that you are low, but during warmer weather the bladder inside the gas tank shrinks slightly (or so I have been told) and you actually have less capacity than you think you do. The workaround is to fill it before it gets that low, I guess.
Any other questions? 
