Which of these do you think is best for Photoshop? I've got an answer in mind but I won't say it... not to mix your opinion
Also, the Dell is obviously a notebook.
Some say the Apple OS works best, but:
Inspiron 17R - N7110
Processor
2nd Generation Intel® Core™ i5-2450M processor (2.50 GHz with Turbo Boost 2.0 up to 3.10 GHz)
Operating System
Windows 7 Home Premium, 64bit, English
Memory1
8GB Dual Channel DDR3 1333MHz
Chipset
Mobile Intel® 6 Series Express Chipset (HM67)
Video Card
NVIDIA® GeForce® GT 525M (128-bit) 1GB
Display
17.3" High Definition (900p) LED Display with Truelife™
Audio and Speakers
SRS Premium Sound™ - 2 speakers @ 2W each
Subwoofer @ 3W
Hard Drive
Up to 750GB2 SATA hard drive (5400RPM)
Optical Drive
Internal tray-load DVD+/-RW
Power
6-cell 48WHr Li-Ion Battery
9-cell 90WHr Li-Ion Battery (Sold Separately)
Camera
1.0MP Integrated 1280x720 native HD Webcam
Wireless
Wi-Fi Bluetooth Options:
Intel® Centrino® Wireless-N 1030 (1x2 bgn + Bluetooth)
Ports, Slots & Chassis
Externally Accessible
(2) USB 3.0
(1) USB 2.0
(1) USB 2.0 with E-SATA & Power Share
HDMI v1.4 Port
VGA Port
Integrated network connector 10/100
LAN (RJ45)
AC adapter connector
Audio jacks (1-line out, 1 Mic-in)
8-in-1 Media Card Reader
Digital (SD) Memory Card
Secure Digital Extended Capacity (SDXC)
Secure Digital High Capacity (SDHC)
Multi Media Card (MMC)
MultiMedia Card plus (MMC+)
Memory Stick (MS)
Memory Stick PRO (MS Pro)
xD Picture Card (xD)
Dimensions & Weight
SWITCH by Design Studio enabled Laptop
Width: 16.50" (418.4mm)
Height: 1.23" (31.3mm) front / 1.40" (35.6 mm) back
Depth: 11.30" (286.8mm)
Starting weight of 7.14 lbs (3.24 kg)
OR
iMAC
Processor & Memory
Processor speed: - 2.66 GHz
Processor Type: - Intel, Core 2 Duo (Penryn)
Number of Cores: - 2
Bus Speed: - 1067 MHz
Cache: - 6 MB L2 cache
64-bit Support: - Yes
Turbo Boost: - No
Installed RAM: - 2 GB
Max. Amount: - 4.0 GB
Amount of Slots: - 2
RAM Speed: - 800 Mhz
RAM Type: - PC2-6400, DDR2, SO-DIMM.
Storage and Media Graphics
Hard Drive: - 320 GB, 7200rpm.
Drive Bus: - Serial-ATA.
Optical Drive: - This unit has an 8x SuperDrive built in.
Optical Bus: - Ultra-ATA/100
Other Media: - None
Display Size: - 20-inch
Graphics Card: - ATI Radeon HD 2600 PRO
Card Memory: - 256 MB
Max. Resolution: - 1680 x 1050
BLU / Coating: - TFT LCD, Glossy.
Networking & Ports and Expansion
AirPort: - Built-in Airport Extreme (802.11 a/b/g/n).
Ethernet: - 10/100/1000BASE-T (RJ-45).
Bluetooth: - Built-in Bluetooth 2.1 + EDR.
Infrared: - For use with Apple Remote only.
Modem: - Optional Apple USB Modem.
USB: - 4 ports (USB 2.0)
FireWire: - 2 ports (1xFW400 and 1xFW800)
Display port: - Mini DVI
Card Slot: - None
Thunderbolt: - No
Operating System and Software
Original OS: - 10.5.2 Leopard.
Maximum OS: - Latest Release.
Recommended OS: - Latest release of Mac OS X
Misc information Repair and Support
Introduction: - April 2008
Discontinued: - March 2009
Diagnostics: - Apple Hardware Test 3A138
New Price (base): - Coming Soon

Some say the Apple OS works best, but:
Inspiron 17R - N7110
Processor
2nd Generation Intel® Core™ i5-2450M processor (2.50 GHz with Turbo Boost 2.0 up to 3.10 GHz)
Operating System
Windows 7 Home Premium, 64bit, English
Memory1
8GB Dual Channel DDR3 1333MHz
Chipset
Mobile Intel® 6 Series Express Chipset (HM67)
Video Card
NVIDIA® GeForce® GT 525M (128-bit) 1GB
Display
17.3" High Definition (900p) LED Display with Truelife™
Audio and Speakers
SRS Premium Sound™ - 2 speakers @ 2W each
Subwoofer @ 3W
Hard Drive
Up to 750GB2 SATA hard drive (5400RPM)
Optical Drive
Internal tray-load DVD+/-RW
Power
6-cell 48WHr Li-Ion Battery
9-cell 90WHr Li-Ion Battery (Sold Separately)
Camera
1.0MP Integrated 1280x720 native HD Webcam
Wireless
Wi-Fi Bluetooth Options:
Intel® Centrino® Wireless-N 1030 (1x2 bgn + Bluetooth)
Ports, Slots & Chassis
Externally Accessible
(2) USB 3.0
(1) USB 2.0
(1) USB 2.0 with E-SATA & Power Share
HDMI v1.4 Port
VGA Port
Integrated network connector 10/100
LAN (RJ45)
AC adapter connector
Audio jacks (1-line out, 1 Mic-in)
8-in-1 Media Card Reader
Digital (SD) Memory Card
Secure Digital Extended Capacity (SDXC)
Secure Digital High Capacity (SDHC)
Multi Media Card (MMC)
MultiMedia Card plus (MMC+)
Memory Stick (MS)
Memory Stick PRO (MS Pro)
xD Picture Card (xD)
Dimensions & Weight
SWITCH by Design Studio enabled Laptop
Width: 16.50" (418.4mm)
Height: 1.23" (31.3mm) front / 1.40" (35.6 mm) back
Depth: 11.30" (286.8mm)
Starting weight of 7.14 lbs (3.24 kg)
OR
iMAC
Processor & Memory
Processor speed: - 2.66 GHz
Processor Type: - Intel, Core 2 Duo (Penryn)
Number of Cores: - 2
Bus Speed: - 1067 MHz
Cache: - 6 MB L2 cache
64-bit Support: - Yes
Turbo Boost: - No
Installed RAM: - 2 GB
Max. Amount: - 4.0 GB
Amount of Slots: - 2
RAM Speed: - 800 Mhz
RAM Type: - PC2-6400, DDR2, SO-DIMM.
Storage and Media Graphics
Hard Drive: - 320 GB, 7200rpm.
Drive Bus: - Serial-ATA.
Optical Drive: - This unit has an 8x SuperDrive built in.
Optical Bus: - Ultra-ATA/100
Other Media: - None
Display Size: - 20-inch
Graphics Card: - ATI Radeon HD 2600 PRO
Card Memory: - 256 MB
Max. Resolution: - 1680 x 1050
BLU / Coating: - TFT LCD, Glossy.
Networking & Ports and Expansion
AirPort: - Built-in Airport Extreme (802.11 a/b/g/n).
Ethernet: - 10/100/1000BASE-T (RJ-45).
Bluetooth: - Built-in Bluetooth 2.1 + EDR.
Infrared: - For use with Apple Remote only.
Modem: - Optional Apple USB Modem.
USB: - 4 ports (USB 2.0)
FireWire: - 2 ports (1xFW400 and 1xFW800)
Display port: - Mini DVI
Card Slot: - None
Thunderbolt: - No
Operating System and Software
Original OS: - 10.5.2 Leopard.
Maximum OS: - Latest Release.
Recommended OS: - Latest release of Mac OS X
Misc information Repair and Support
Introduction: - April 2008
Discontinued: - March 2009
Diagnostics: - Apple Hardware Test 3A138
New Price (base): - Coming Soon