These make a nice first car...

...But you probably will want to upgrade after awhile. I drive a 99' Geo Metro. I am only 21, but after driving this car for a few years, I really want something more powerful and safe, that is higher up off of the ground.
My Geo is a 4 cylinder, and in my family we joke that it's one step up from a lawnmower. I have heard that they do actually make 5 cylinder ones now, but mine is a 4. The engine is tiny, as is the whole car. I have a 5 speed manual transmision, and no A/C, and no rear defrost.
I have not attempted driving this car in high heat places, and my parents usually rent a car if they are going to be driving on vacation. These are great commuter cars, but they are horrible to try and drive long distances in.

The good things: This car is extremely reliable. I have driven mine all over the place for years without any break downs, or malfunctions. The gas milage is awesome, I usually get about 30 mpg, freeway driving. Usually, I only pay about 10 bucks to fill up my cars gas tank when it's on empty. It's an 8 gal. tank. Get it in for oil changes,tire rotations, etc and the car will go forever.
The seats are fairly comfy. The radio works well, the floor/dash vent heating is great for cold days,and the back folds all the way down flat which is wonderful for transporting large items like TVs. There are daylights [basically your headlights are on at 50% power], so other people can see you more easily during the daytime.
Since it is such a small car, It can pull off U-Turns in places where most people couldn't dream of even trying. Parking is a breeze...even parking crooked, 9 times out of 10 it will *still* be within the lines. Road vibration is not bad if you aren't driving long distance. It's a cute car, and great to learn in due to the extreme forgiveness it gives you when learning stick shift. Steering is pretty good, and the car takes turns pretty easily...just don't try and go really fast.

Bad Things: First of all...this is a *Small Car*. 4 people barely fit and if you are tall, expect to be squished. This car is not good for long distance traveling. My family [3 people] tried it, and we rent cars now. There just is not enough room for people, luggage, and snacks without it feeling claustrophobic. The road vibration and noise are fairly loud. The air seals on my windows and doors still whistle faintly even when everything is shut as tight as possible. Opening windows on the freeway is not fun...It makes this annoying deep air sucking noise that will drive you insane and hurt your ears. Expect to rely on your vents if you don't have A/C. The vents work great..the defrost however, is another story. It usually doesn't work until 15 min after being turned on full blast, with the windows down.The windows tend to fog up easily, and also hold water on the outside making visibility really poor. The only solution I have found is the RainX and FogX, since I have no rear defrost. The car is very low to the ground, which is not fun when it's raining because visibility can be really,really poor. This is Especially true if you get stuck behind big semi's or the like. There are airbags, but I feel like I am basically driving an aluminum can on wheels...if I get in an accident, it will probably crunch up pretty badly.
The car shakes alot on the freeway, and this is okay for a little while, but it really gets tiring on the arms/hands,legs and feet after a few hours. Going uphill in a Geo is S L O W going. These are not powerful cars. They lose speed quickly up steep hills, and the whole car is straining to make it even with downshifting. It goes at an absolute crawl uphill.
Blind Spots are prelevant, and getting on the freeway can sometimes be scary.
Basically, these are wonderful Commuter Cars. It's a good car to learn on,great deal for the money, and mine lives up to my expectations based on the car it is. If you just drive short distance, or commute to work this car would probably work just fine for you.