Try yourselves and then Decide Bala.
But if you still want us to mention ,then go with Kaspersky.Kaspersky only use resources when it scans...(not in realtime).Me currently using Kaspersky.
G-data uses High system resources.
AVG improved a lot from their past versions specially in detection rate.You can try it.
Bitdefender is very good but the manufacturing company should still have to work on the resource usage by their product and specially net slowdowns.