GPUs fabricated at the 28nm process node are going to be very appealing compared to current GPUs. We've been stuck at 40nm since the Radeon HD4770 appeared in April 2009. The process shrink should allow future GPUs to be faster while using less power and generating less heat and noise than currently-available products.
If you're buying a new GPU today, the Radeon HD6950 provides good bang for the buck (as little as $200 after rebate). It should perform well at your monitor's native resolution of 1920x1200.
i7-4770K, H70, Gryphon Z87, 16 GiB, R9-290, SSD, 2 HD, Blu-ray, SB ZX, TJ08-E, SS-660XP², 3007WFP+2001FP, RK-9000BR, MX518