southernlady posts has some good info up in the sticky .
http://neurotalk.psychcentral.com/showthread.php?t=4535

but any of the name brands should be good.
mcafee
bitdefender
pcillin
AVG
etc

for easy - I liked bitdefender and AVG stuff
but mcafee has a virus scanner called stinger - that will do a quick check for viruses - {but maybe the others do to- i just found mcafee first at the time}

some have free trial programs to see if you like the way they work

some have a free downloadable AV version & even an online scanner

don't forget about adware and spyware
and
spam /email protection