I've used NOD 32 before and it's pretty reliable. I've never gotten a false positive from it before (unlike with AVG) and it doesn't slow down my system like Kaspersky or become incredibly intrusive like Norton.
For a free but not really legal option, if you're using XP or 32-bit Vista, consider getting the older version of NOD32 like 2.7. Due to a bug in its trial version, you can actually just reinstall it every 30 days and it will still update and work like normal. This trick doesn't work with the newer 3.+ versions or with the 64-bit versions, though.
If you want to buy it, NOD 32 is a bit hard to find in Malaysia. A list of shops that sell them retail can be found
here, but it is recommended that you call them in advance as they may not actually keep it in stock. It can also be purchased online
here. Either way, a one-user one-year license will cost you about RM 140, making it one of the more expensive AV options in Malaysia.