things to use instead of WD-40

 Water Displacement formula #40 smells good... but quite frankly, it's a lousy product whose only saving grace is that it's dirt cheap.

 Here are some great products to use instead - all of these are available in hardware stores, automotive stores, and online:

for rust removal
1st choice: Ospho or other brand of straight phosphoric acid (Coke works in a pinch if you're patient)
2nd choice: Evap-O-Rust

for rust prevention
1st choice: No-Rust™rust preventative spray from Slide™
2nd choice: LPS3 Premium Rust Inhibitor

for penetrating oil / loosening stuck fasteners
1st choice: KB-88 from LPS
2nd choice: Kroil
(Liquid Wrench was good until they changed the formula in the mid-1980s - it sucks now)

for water displacement / degreasing
1st choice: LPS-HDX
2nd choice: QD Electronic Cleaner from CRC
3rd choice: Braklene from CRC

silicone lubricants (for temperature extremes or lubricating plastics)
1st choice: Permatex 80070
2nd choice: CRC Heavy Duty Silicone

 Under no circumstances should you ever purchase anything from PB Blaster or any of the "Blaster" spray lubricant products.  They are just clones of the best-selling brands with more solvent/carrier and less of the active ingredients, and sold at a higher price.  In tests, they all perform worse than WD-40...