Not Voodoo (Professor Frontier's amazing chemistry techniques website)

Periodic Table (cool)

Boiling Point Estimation (and other useful info)

Common Name Reaction

NMR Solvents

NMR Data Predict & Stimulate

IR Table Chart

Molarity of Concentrated Reagents

Dillution Calculator

Organic Chemistry Information

Common Organic Chemistry

Organic Syntheses (Essential resource)

Organic Chemistry Portal (Tons of useful organic chemistry content)

Noble Prize Winners in Chemistry

Chemistry Reference Resolver

Tricks and Tips for growing quality crystals