I've been using the disposable Max and Max Lite by Howard Leight since last summer and have been very pleased with their fit, noise reduction, and price. Good link, Joe.
I have E-A-R UltraFit ( NRR-25) and MAX ( NRR-33 ) in the right pocket, but prefer my ER-4 MicroPro earphones, 20 gig I-Pod and enough road to listen to all the music.
The best earplugs are those that are custom made, based on a mold of your ear canal. You can get them configured to let some sound come through or even for stereo output. One of my better $100 investments.