Hi,

I am listing down the best books for GATE EC:

1. Communications - Modern Digital and Analog Communications Systems by B.P. Lathi

2. Signals & Systems - Signals and Systems by Alan V. Oppenheim, Alan S. Willsky, S. Hamid Nawab

3. Electronic Devices - Semiconductor Physics and Devices by Donald Neamen

4. Electromagnetic Theory - Principles of Electromagnetics by Matthew N. O. Sadiku

5. Control Systems - Control Systems Engineering by M. Gopal, I. J. Nagrath

                                  Automatic Control Systems by Benjamin Kuo

6. Digital Electronics - Digital Design by M. Morris Mano

                                    Modern Digital Electronics by R. P. Jain

                                    Microprocessor Architecture, Programming and Applications with the 8085 by Ramesh Gaonkar

7. Analog Circuits - Microelectronic Circuits: Theory and Applications by Adel S. Sedra, Kenneth Carles Smith

                               Op-Amps & Linear Integrated Circuits by Ramakant Gayakwad

8. Engineering Mathematics - Higher Engineering Mathematics by B. S. Grewal

9. Network Theory - Engineering Circuit Analysis by William H. Hayt

                                 Network Analysis by Mac Van Valkenburg

Hope this helps.

Cheers!