I've had some awesome cockatiels! They also come in some interesting color combinations now. They can be very, very sweet and really bond to humans. Because of that strong bond - they can pace back and forth and demand your attention until you give it them. A few minutes after you walk in the door spent on him/her will go a long way - just greet and let out of the cage, etc.
I've had both males and females. I will warn you...the females can become cronic egg layers. Males can become talkers and have sort of a high pitched voice but can be clearly understood. They also love to whistle and can pick up tunes fairly easily. In my experience, Males that are kept as single birds, make the best talkers. I've never had a female talk. However, I've had some really, really, sweet, wonderful, little hens! Both males and females LOVE to have their heads/crest scratched...THEY LOVE IT! I used to have a little male that would walk over with his head down asking for it...he would have really exaggerated "yawns" everytime I would scratch his head and orange cheeks. He was really a good little guy!
It's important to introduced them to a wide variety of foods while they are very young...othewise they may not develope much of a desire to try new and different things. These are desert birds so they naturally like to eat foods that are on the dry side... also, mine have always seemed to like veggies better than most fruits.
I would opt for a hand fed baby that has been weaned onto a pelleted diet. Sometimes they can be sexed based on color mutations - sometimes they can't.
You may also find one that is being re-homed. Make sure you handle the bird if you go for one that is being re-homed...don't take the current owners word for it. You need to handle the bird.
You need to make sure it is hand tamed.
I've had really nice cockatiels that were parent raised...that turned out to be really sweet - it just depends on the bird and frankly its positive or negative experience with human beings.
One negative that I need to mention...because of their unique feather structure that they share with their cousins, the cockatoos - they are dusty. I would not keep them next to your electronics or anything like that.
All in all, I can highly recommend them. I don't currently have one - but a couple of weeks ago I saw the cutest little male on CL and I was very tempted! I just don't have the time right now to dedicate to a new bird.
Keep us posted and let us know what you decide...and you must post pictures!