As far as I know, they're all good quality boards (I have a P8Z77-V LK myself), so it would come down to which feature set works the best for you.
The G45 has Thunderbolt, obviously, but only has two SATA-III ports (versus four on the others).
The P8Z77 only has two PCI-e x1 slots (versus four on the others), but has four USB3.0 headers, versus the others' two.
The P8Z77 is also the only board between the three that has legacy PCI support or WiFi.
Personally, I don't require any of those features - I'd go for the GD65, if possible, as it's the cheapest on Newegg, and has the most overall expandability: http://www.newegg.com/Product/Product.aspx?Item=N82E16813130643
(dunno about your shop).