I'm in the gym 3 days a week for the last 3 years. Mostly freeweights.
I stick with the basics - squats, deadlifts, and bench. I will throw in other exercises such as curls, triceps, shoulders. I use different variations to keep the muscles guessing.
I will also change my routine every 4 - 6 weeks to keep things fresh. Right now I'm doing a light/heavy weight training type routine.
Here is a good site that I use. It has about 2000 pages of info.