A higher clocked Phenom II x2 will give you better performance in modern games than an athlon II x3 or x4 because of the way games are threaded. I monitor my quad core's performance and most games will only use up to 50% of my CPU at any time which indicates they only use 2 threads worth of data. GTA4 will benefit from more cores but apart from that not much else will so you'd be much better off with the level 3 cache.
The test is based soley on 1 benchmark against cost which is not a good indicator of overall performance and therefore overall value. if you wanna buy a CPU that provides good value for money to run passmark then its a good list lol
You'll also notice in the other graphs that a lot of the Phenom II's don't have a price next to them which would exclude them from the value charts. Also, what is at the top of the chart?