I have all the major consoles, so my advice (if you only can buy one) is.
Take the 15 most interesting games that you can find, then look at what you need to play them.
My current favourite console is the Nintendo DS. Last console games i enjoyed was Zelda Twilight Princess,God Of War 2,Super Paper Mario.
Currently playing Half Life episode 2.
Long story short, buy games first, then what you need later.