This is just going by what I think will have the best specs then brand name over no name if they are the same.
1. A-DATA 2x1GB DDRII Over Clock Extreme Edition DDR2 800+
2. APACER AM1 DDR2 800 2GB CL5 128X8
3. 2 x 1GB Standard 128M X 64 Non-ECC 800MHz 240-pin Unbuffered DIMM (SDRAM-DDR2, 1.8V, CL5)
4. CORSAIR DDR2 KIT 2X1G 675MHZ HEAT SPRED.