MSE Microsoft Security Essentials and there's a free Malwarebytes and both are great with trainers.
I have been using Panda for a good while. It works great and has excellent reviews. Links for review and Panda.
**I have always found it easiest with any AV to make an "exclusion" folder to keep my CH trainers in. This mitigates any AV problems right from the start.
Though I suppose if PWizard finally loses it one day, he could bork all of our PC's... lol.
It's not so much the antivirus brand than the ease of excluding files and folders from being scanned.
The OS we play with comes from Microsoft and I still think that the creator(s) should know better how to protect themselves, that's why I'm using Microsoft Security Essentials.
I use F-Secure and it works well and the realtime scan isn't that heavy most of the time and the excluding works well it usually asks me if I wanna let trainers run but rarely it quarantines it, luckily you can just exclude the folder and restore it from quarantine.
* Updated game trainers and cheats daily
* Get notified when new cheats are added
* Request which games get new trainers
* Priority support with any problem