With everything in downtown Geneva these days (minus the congestion of downtown Naperville), I'd say their best bet may be checking out one of the places mentioned -- these are some of the best in the western burbs right now.
If they're interested in checking out downtown Naperville, I personally think that Hugo's, Catch 35, La Sorella (a "Francesca" restaurant), and Tango all are pretty solid. Rizzo's is a nice place to grab a drink (downstairs bar), but, while friends like it, I'm not sold on their food. A bit off the beaten path is Adelle's in Wheaton -- a nice, romantic spot, and worth checking out, IMO.
Finally, a good 1/2 way point right off of I88 may be Sequel in Lombard (formerly Bistro Banlieue). I'm a bit embarrassed to admit that I haven't yet been there, but it's the re-vamped Bistro Banlieue, which was one of our longtime favorites.