which intel processors are better?

:confused:I am in the market for a new PC but am confused by all the different intel processors. Its obvious some retailers are using lesser processors to cut costs. I was wondering if someone could put them in order for me. Is there a general rule? Thanks

Corei5-750 2.66GHz
Core i7 860 2.8GHz
Core i3 540 3.06GHz
Dual Core E5300 2.6GHz
2 Duo E8400 3.00GHz
Dual Core E6300 2.8GHz

General order, fastest to slowest:

Core i7 860 2.8GHz
Core i5-750 2.66GHz
Core i3 540 3.06GHz - I haven't seen a test on this one, so it may be lower down in the rankings
2 Duo E8400 3.00GHz
Dual Core E6300 2.8GHz
Dual Core E5300 2.6GHz

Note that the Core i5 and i7 out of that list are quad core, the others are all dual core. The Core i7 860 has Hyperthreading as well, so Windows will see it as an 8-core CPU.

The Core i3 contains a built-in graphics chip on the processor itself, so for low-end usage a separate graphics card is not needed, though it is unsuitable for high-end gaming.