I prefer to shoot landscapes, nature, and architecture. I do some portraiture (family shots mostly), and prefer natural light over reflectors, flashes, and studio setups.
Lightroom is awesome. I was a Photoshop snob for years, and now I use it once in a while for fine-tuning a picture. If you have or will take more than a thousand photos, Lightroom is the only way to go. Aperture, iPhoto, and Picasa don't hold a candle to it, IMHO. Shoot RAW every time; you'll always get some information tossed out when you shoot JPG.
One of my favorite subjects is fireworks - it requires both skill and luck. You must use a tripod, set for "bulb" exposure, use a trigger for the shutter, and just guess how long to keep the image exposed. You learn after checking the image after few shells if you've got the timing right. You take about 100 shots, maybe 20 will come out right. Best of all, you can cover the lens with your hand, keep the shutter open, and then have multiple fireworks appear on one exposure, effectively "painting" the image of fireworks that were 30 seconds apart.