Sapphire's HD 6450 comes with a low-profile design, passive heatsink and native full-size HDMI. Together with AMD's UVD 3 video encode acceleration that provides excellent video decode capabilities this could well be your next HTPC card.
Slow computer got you down? Maybe a hardware upgrade should be in your cards, if so this guide to the Fundamentals of Upgrading a PC is an invaluable read. PCSTATS Tips