1. Which is theLatest Series of PS2.
Version 7. (SCPH-3900x)
2. Whats the Major difference in PAL and NTSC systems as I know Pal systems are U.K based and NTSC systems are USA based, is there any other difference like speed and Mainboards ETC.
The only difference is the way they display the information. (Due to the television standards of the areas.) There IS a graphics difference between a Japanese NTSC PS2 and a USA NTSC PS2, but it has no real effect on the gameplay, or the look. (Something about graphics chips in the Japanese ones that the goverment also uses, forcing them to change the design for the USA PS2s...)
3. How should I check the Serial No. of BIOS of PS2 before buying a system because the dealers here in my country (Pakistan) will cheat me and they change the upper case of PS2 and sell me old one.
Short of booting it up, there is no way that I know of to check the SCPH Number, without trusting the box. There is a hole in the bottom of the box that has shows the Serial number on the case, but as you said, the dealers could switch it out on you. You might want to consider ordering one online. Should be a similar price, minus the shipping...
4. Someone told me that the "R" series PS2 Models are the best, is it true ?
No Clue. I don't even know what a R-series PS2 is...
5. Any recommendations to buy any model, which is more stable and error free.
Don't get a Gen4. My brother and his friend both have a gen4 and they've both broken down in less than a year. They can't play any of the newer games anymore.
My Gen7 (SCPH-39001) seems to work great, but I only bought it shortly before Christmas, so it hasn't had time to generate any problems...
Hope this helps!
