Can someone tellme which is the best circuit simulator rather than Spice.....?

 

SPICE is an acronym for "Simulation Program with Integrated Circuit Emphasis". It was originally developed using mainframe computers.

It's sort of a generic name now.

There are many circuit simulators using PSpice (the P means that it runs on a personal computer).
Linear Technology's LTSpice is good and free. Google is your friend here.

Texas Instruments offers Tina TI for a free download. Some like that interface better.