For me, I think the lights, props and gadgets drew me in first -- the big dice and big numbers on High Rollers ('74-76, and no, I couldn't tell you which format), the big lever and the wheels on The Joker's Wild (the first game show I recall watching regularly), and of course all the bells and whistles on the pricing games on The Price is Right. It didn't hurt that in Hebrew day school, we had a TV in the room for several of the years I was there, and when we'd have recess and had to stay indoors we could watch Price and The $20,000 Pyramid (and, for a brief time, Pass the Buck) all we wanted. :-)
Of course, once I got in the habit of watching a few game shows, I'd watch as many as I could when I was home from school. I got hooked on Password Plus early (though I wondered where Password '79, mentioned in the local paper's TV book, had gone) and tried to play along as well as a 9-year-old could, I'd do likewise with Family Feud, I'd follow the Xs and Os on Hollywood Squares even though I didn't get most of the zingers, and on a family trip to Florida I insisted on watching Whew! each morning.