It is the best video card I can upgrade to?

Operating System: Windows Vista™ Home Premium (6.0, Build 6002) Service Pack 2 (6002.vistasp2_gdr.110617-0336)
Language: English (Regional Setting: English)
System Manufacturer: HP-Pavilion
System Model: GS354AA-ABA a6203w
BIOS: Phoenix - AwardBIOS v6.00PG
Processor: AMD Athlon(tm) 64 X2 Dual Core Processor 4400+ (2 CPUs), ~2.3GHz
Memory: 3454MB RAM
Page File: 1631MB used, 5475MB available
Windows Dir: C:\Windows
DirectX Version: DirectX 11
DX Setup Parameters: Not found
DxDiag Version: 7.00.6002.18107 32bit Unicode