My objective for now is to get a hold of the games that came with the white strip, the games released before mid-2005. It is important to note that, there are many different versions of the same games out there, but they are not as valuable as each other from a collector`s point of view.
One example is the Fatal Frame serie. These games were pretty rare at the time, until they were reprinted at the end of the ps2`s active life. The reprints are selling for 25$-30$ new right now, and there are plenty of them to go around. However, the first print Fatal Frames came out with a white strip, and they are very rare.
There isn`t much difference between the artwork of the original games and the reprints.
Many games were also rereleased as "greatest hits" versions. The "greatest hits" version isn`t as valuable as the original, of course. Its very easy to spot a "greatest hits" version as it is reflected on the artwork of the game. However, one should be very carefull as there are many uncrupulous sellers on ebay advertising games for sale with a stock picture of the original release and sending "greatest hits" versions to their customers.
One more example of multiple versions of the same game is Resident Evil Code Veronica X ; it came out as an "anniversary" version that included a demo of devil may cry, a standard black label version and a greatest hits version. It also came out as part of "Resident Evil : The Essentials" boxed set released in 2007 - I do not have this set but I would believe the version contained in it is a reprint of the standard black label version, minus the white strip.