This time of year, Popeye's is probably approachable, especially with no snow. It's not worth the wait in high season, but it's pretty good. On Main across from the marina
811 Wrigley Dr
Lake Geneva, WI 53147
(262) 248-4381 - close call
popeyesonlakegeneva.com
Ignore the fact that Google Maps says "Popeye's Chicken and Biscuits" unless there's been a radical change in the last 6 months.
Seafood is pretty good, and some Greek items -- skordalia's a winner.
Cactus Club & Cantina is better-than-decent Mexican-American. I've eaten there a couple times and enjoyed it. It's not a taqueria, it's not Salpicon, but you can have a good time.
430 Broad St
Lake Geneva, WI 53147
(262) 248-1999
Tempura House, when I was there a couple years ago, was excellent and a decent value for a tourist town. At that point, the building was barely converted from a home, some diners ate in an obvious living room, others in a dining room, etc.
Tempura House Japanese Cuisine - more info »
306 Center St, Lake Geneva, WI
(262) 249-8822
Chicago Pizza is pretty good.
150 Center St, Lake Geneva, WI
(262) 248-8544
If you need some references elsewhere around the lake, there's a few places in Williams Bay, Delevan and Fontana, but most of the action is in Geneva.
One place worth looking into off the beaten path
Mars Resort & Restaurant
W4098 S Shore Dr, Lake Geneva, WI
(262) 245-5689
Old fashioned resort, good fish, homey kind of place
What is patriotism, but the love of good things we ate in our childhood?
-- Lin Yutang