avoid dell and lenovo. alienware is usually overpriced.
asus, msi, and hp are some options, as well as custom build shops/websites.
if you are doing photo work, a big decision will be if you want a 10bit display or to use an external 10bit monitor? im not sure if cs6 supports 10bit display, or if there are any known issues. you may have to check on the photoshop forums for info. msi and hp offer some screens rated 100% (or close to) adobe rgb on certain models. those screen's and/or external 10bit monitors will also need a quadro to enable 10bit. a quadro m2000m might be enough for photo work, a quadro m3000m more for video/premiere. some of the laptops also use xeon processors, like the e3-1505m v5 and ecc memory. xeons are for workstation grade hardware, and should be a sign the laptop is slightly better quality. if you don't need alot of space for media, you can get a 256 or 512gb sata ssd or a pcie m.2 (even faster), and then a slow 1tb hdd for mass storage and backups.
if you don't need 10bit, you can just look for a normal laptop, it will be a bit cheaper without the quadro. i7-6700hq and gtx 965m are similar to the xeon and quadro m3000m listed above.
if you want it to last longer, make sure you get one with thunderbolt 3 and usb 3.1 (gen 2, 10gb). they should allow more options as some new devices will only be available for those fast connections.
im not saying to buy these, but here are some examples of the regular laptops with the pcie m.2 ssd and thunderbolt features. the other mfg's including hp should have similar models.
this asus has the slightly slower gtx 960m (should still ok for photo), but it has all the other features, like 16gb memory and 512gb pcie m.2 ssd and thunderbolt
this asus has a smaller 128gb pcie m.2 ssd, but faster gtx 970m (good for video), larger 17" screen, and thunderbolt
http://www.amazon.com/G752VT-DH72-Gaming-Discrete-GeForce-Titanium/dp/B01578ZN0Q