I have in my PC now AMD Athlon 64 3500+ 2.2GHz
Ram 1.25Gigs

At this point I can upgrade memory to 4 gigs for $80.00
These are the chips my board accepts: Which one would be the best processor for Emulators and Mame and is it worth upgrading:
AM2 Athlon 64 FX FX-62(F2) 2800MHz (2x1MB,2000,Socket AM2) YES
Phenom Quad-Core 9750 (B3) 2400MHz (4x512KB,3600,Socket AM2+) YES
Phenom Quad-Core 9650 (B3) 2300MHz (4x512KB,3600,Socket AM2+) YES
Phenom Quad-Core 9550 (B3) 2200MHz (4x512KB,3600,Socket AM2+) YES
Phenom Quad-Core 9350e (B3) (65W) 2000MHz (4x512KB,1800,Socket AM2+) YES
Phenom Quad-Core 9150e (B3) (65W) 1800MHz (4x512KB,1600,Socket AM2+) YES
Phenom Quad-Core 9100e (B2) 1800 MHz (512KBx4,1600,Socket AM2+) YES
Phenom™ Triple-Core 8750 (B3) 2400MHz (512KB x3,3600,Socket AM2+) YES
Phenom™ Triple-Core 8650 (B3) 2300MHz (512KB x3,3600,Socket AM2+) YES
Phenom™ Triple-Core 8600 (B2) 2300MHz (512KB x3,3600,Socket AM2+) YES
Phenom™ Triple-Core 8450 (B3) 2100MHz (512KB x3,3600,Socket AM2+) YES
Phenom™ Triple-Core 8400 (B2) 2100MHz (512KB x3,3600,Socket AM2+) YES
Phenom™ Triple-Core 8250e (B3) 1900MHz (,3600,AM2+) YES
Phenom™ II Triple-Core 705e (C2) (65W) 2500MHz (3x512KB,4000,AM2+) YES
Phenom™ II Triple-Core 700e (C2) (65W) 2400MHz (3x512KB,4000,AM2+) YES
Athlon II Quad-Core 605e (C2) (65W) 2300MHz (512KB X 4,4000,Socket AM3) YES
Athlon II Quad-Core 600e (C2) (65W) 2200MHz (512KB X 4,4000,Socket AM3) YES
Phenom™ II Dual-Core 550 (C2) (80W) 3100MHz (512KB X 2,4000,Socket AM3) YES
Phenom™ II Dual-Core 545 (C2) (80W) 3000MHz (512KB X 2,4000,Socket AM3) YES
Athlon II Triple-Core 405e (C2) (45W) 2300MHz (3x512KB,4000,AM2+) YES
Athlon II Triple-Core 400e (C2) (45W) 2200MHz (3x512KB,4000,AM2+) YES
Athlon II Dual-core 255 (C2) (65W) 3100MHz (1MB X 2,4000,Socket AM3) YES
Athlon II Dual-core 250 (C2) (65W) 3000MHz (1MB X 2,4000,Socket AM3) YES
Phenom™ II Dual-Core 245 (C2) (65W) 2900MHz (1MB,4000,AM2+) YES
Athlon II Dual-core 240e (C2) (45W) 2800MHz (1MB X 2,4000,Socket AM3) YES
Athlon II Dual-core 240 (C2) (65W) 2800MHz (1MB X 2,4000,Socket AM3) YES
Athlon II Dual-core 235e (C2) (45W) 2700MHz (1MB X 2,4000,Socket AM3) YES
Athlon II Dual-core 215 (C2) (65W) 2700MHz (1MB X 2,4000,Socket AM3) YES
AM2 Athlon 64 x2 5200+(F3) (65W) 2600MHz (2x1MB,2000,Socket AM2) YES
AM2 Athlon 64 x2 5200+(F2) 2600MHz (2x1MB,2000,Socket AM2) YES
AM2 Athlon 64 x2 5200+ (G2) (65W) 2700Mhz (2x513KB,2000,AM2+) YES
AM2 Athlon 64 x2 5200+ (G1) 2700Mhz (2x512KB,2000,Socket AM2) YES
AM2 Athlon 64 x2 5000+(G1) 2600MHz (2x512KB,2000,Socket AM2) YES
AM2 Athlon 64 x2 5000+(F3) 2600MHz (2x512KB,2000,Socket AM2) YES
AM2 Athlon 64 x2 5000+(F2) 2600MHz (2x512KB,2000,Socket AM2) YES
AM2 Athlon 64 x2 4800+(G2) (65W) 2500MHz (2x512KB,2000,Socket AM2) YES
AM2 Athlon 64 x2 4800+(G1) 2500MHz (2x512KB,2000,Socket AM2) YES
AM2 Athlon 64 x2 4800+(F2) 2400MHz (2x1MB,2000,Socket AM2) YES
AM2 Athlon 64 x2 4600+(F2) (65W) 2400MHz (2x512KB,2000,Socket AM2) YES
AM2 Athlon 64 x2 4400+(G1) 2300MHz (2x512KB,2000,Socket AM2) YES
AM2 Athlon 64 x2 4400+(F2) 2200MHz (2x1MB,2000,Socket AM2) YES
AM2 Athlon 64 x2 4200+(F2) 2200MHz (2x512KB,2000,Socket AM2) YES
AM2 Athlon 64 x2 3800+(F3) 2000MHz (2x512KB,2000,Socket AM2) YES
AM2 Athlon 64 x2 3800+(F2) (35W) 2000MHz (2x512KB,2000MHz,Socket AM2) YES
AM2 Athlon 64 x2 3600+(G1) 1900MHz (2x512KB,2000,Socket AM2) YES
AM2 Athlon 64 x2 3600+(F2) 2000MHz (2x512KB,2000,Socket AM2) YES
Athlon X2 BE-2400 (G2) 2300Mhz (2x512KB,2000,Socket AM2) YES
Athlon X2 BE-2350 (G2) 2100Mhz (2x512KB,2000,Socket AM2) YES
Athlon X2 BE-2350 (G1) 2100Mhz (2x512KB,2000,Socket AM2) YES
Athlon X2 BE-2300 (G2) 1900Mhz (2x512KB,2000,Socket AM2) YES
Athlon X2 BE-2300 (G1) 1900Mhz (2x512KB,2000,Socket AM2) YES
AM2 Athlon 64 4000+(F3) 2600MHz (512KB,2000,Socket AM2) YES
AM2 Athlon 64 4000+(F2) 2600MHz (512KB,2000,Socket AM2) YES
AM2 Athlon 64 3800+(G1) 2400MHz (512KB,2000,Socket AM2) YES
AM2 Athlon 64 3800+(F3) 2400MHz (512KB,2000,Socket AM2) YES
AM2 Athlon 64 3800+(F2) 2400MHz (512KB,2000,Socket AM2) YES
AM2 Athlon 64 3500+(G1) 2200MHz (512KB,2000,Socket AM2) YES