Hard drive help for my system

Which hard drive do you think would work better for my system? i am only getting ONE hard drive.

PCPartPicker part list / Price breakdown by merchant / Benchmarks
CPU: Intel Core i5-3470 3.2GHz Quad-Core Processor ($199.99 @ Newegg)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($34.99 @ Newegg)
Motherboard: ASRock H77 Pro4/MVP ATX LGA1155 Motherboard ($87.55 @ Newegg)
Memory: G.Skill Ares Series 8GB (2 x 4GB) DDR3-1600 Memory ($37.99 @ Newegg)
Video Card: Sapphire Radeon HD 7870 GHz Edition 2GB Video Card ($251.97 @ Newegg)
Case: Cooler Master CM 690 II (Black) ATX Mid Tower Case ($64.99 @ Newegg)
Power Supply: SeaSonic S12II 620W 80 PLUS Bronze Certified ATX12V / EPS12V Power Supply ($83.98 @ Newegg)
Optical Drive: Lite-On iHAS124-04 DVD/CD Writer ($22.98 @ Newegg)
Mouse: Dell 468-7409 Mouse Wired Optical Mouse ($26.97 @ Newegg)



Storage: Western Digital Caviar Black 1TB 3.5" 7200RPM Internal Hard Drive ($109.99 @ Newegg)
Storage: Samsung Spinpoint F3 1TB 3.5" 7200RPM Internal Hard Drive ($88.98 @ Newegg)