What GPU to go with for a 46' 1080p HDTV

[ComputerNaiveté]

I plan on using this as my computer monitor:


46" Quattron 1080p 120HZ LED TV

• 1080p resolution
• Quadpixel technology with 4 color filter
• 120hz fine motion enhanced
• 4ms response time; built-in ATSC/QAM/NTSC tuners
• Wide viewing angles (176º h x 176º v)
• Ultra brilliant led system; high brightness
• 4 HDMI
• PC input
• Energy star compliant

What GPU would give me the best quality? Or should I go with the dual card option and if so with what?