Anti Virus Software

Can anyone tell me if it is worth buying BitDefender for my home computer. I spend a lot of time surfing the internet and doing research. I currnetly have Avast on my system, but recently had the computer contact a virus. It is being looked at by a computer repair company now. A friend told me about Bit Defender. he says it is one of the best anti virus software out there. A 10 ten review site also rank it number one.
Any input from a computer tech expert would be greatly appreciated.