I mostly agree with the above answer. If you want all the original goodness, try this:
Red/Blue/Green/Yellow -This will be the original 151, like Mew, Dragonite, Pikachu, and Lapras.
Gold/Silver/Crystal -The second generation includes pokemon like Spinarak, Lugia, Tyranitar, and Pichu.
Sapphire/Ruby/Emerald -The third Generation includes pokemon such as Linoone, Beautifly, Wynaut, and Rayquaza.
Diamond/Pearl/Platinum -The fourth generation is the first DS one. This has pokemon like Garchomp, Mammoswine, Yanmega, and Giritina.
Black/White -The latest installment in the pokemon series. Generation V includes Klinklang, Krookodile, Conkeldurr, and Unfezant.
Once you've played through, migrate all the Gameboy games's pokemon to Diamond/Pearl/Platinum. Once that is completed, migrate them to Black/White. Good luck getting all 649!
Gotta Catch 'em all!
P.S. You can substitute Red/Blue/Green/Yellow for Fire Red/Leaf Green for better graphics and playing. The same may be done with Gold/Silver/Crystal for Heart Gold/Soul Silver. Hope this helped!