Some very modern PC games, video encoding, even FarmVille.
Hmmmm Farmvilled eh, I'm not any kind of computer wiz, but I've recently come across something myself that might aid your performance in this regard, but I can't be sure if your "issues" with the game are entirely due to your setup and not the game's limitations, coding, et cetera.
I don't play it or browser-based games, but I have made a tweak to my browser for a performance boost in general.
It's called a RAMDISK
What browser do you use?
It essentially utilizes your RAM (not Hard Disk) for, I hope this is correct, a cache for data in whatever browser you choose to employ it, which I guess more or less gives you the incredible access speed boost of RAM (memory) as opposed to spinning discs of your standard model-T hard drive.
Now, if you're rolling with an SSD then I can't say what the benefits will be when compared. But I believe using RAM is the fastest if you have RAM to spare.
Also, if the specific browser is set to utilize your video graphcis to speed up things may also help.. I don't REALLY know much about it all though, just ideas
RAMDISK seems to be boosting my browsing up though, I will run some "experiments" and get back to you