TABLES OF INTEGRALS

There are many interesting tables with evaluations of definite and
indefinite integrals.

The table by
Gradshteyn and Rhyzik
is very complete. We are in the process of proving all the formulas in it.

The proofs can be found in
here

The Tilu site allows you to evaluate many
interesting integrals.

The table by
Alexander Apelblat is compact and it contains several gems.