If I want it, I buy it.
I actually prefer to buy loose, since i am probably the biggest hater of boxes and manuals on this board. I get pissed at having to trade off those infernal boxes and manuals.
I'll take the carts in any condition, but i PREFER better condition carts. one of these days, i'm going to de-sticker my snes and genesis carts that have stickers - i got a ton of former rental genesis games..not so much for any system but genesis.
Systems I am PICKY about. I HATE crappy condition systems; and I for the most part REFUSE to buy anything but MODEL ONE/LAUNCH hardware. there are a few exceptions. I consider the "Revisions" of the original design ps2 to all be the "first" model, since they all look the same anyway. However, I won't touch a flip top "pstwo". While a heavy sixer was not NECCASSARY for me, i was overjoyed to get one, and forked out what i needed to fork out to get it, But any six switch 2600 will do me fine....
exceptions being, I bought an atari XEGS instead of, say, an atari 400 computer, for compatibility reasons, And i got a silver/black common ti99/4a for the same reason. 'Apparently, the c64 i just purchased is a "later model", But it's still the breadbox - still the one I remember.
As for controllers - they MUST be first party. MUST!!! Although I DO use atari 7800 pads on c64, as well as atari systems, they are still a first party controller, which i associate with QUALITY. I've had no more than two offbrand genesis pads and they both broke quickly; offbrand n64 memory cards took a dump in the middle of a season of all star baseball 2000(the only season I ever came close to finishing in a sports title)...
Hrm, I think that's all my rules. heh.