I'd love to be able to recommend Two Brother's - it's the closest to my house... but for anything but the most basic, it's not worth the trouble. Plus, the hours are pretty limited.
For me, that leaves St. Charles or Elmhurst Winemakers... it's pretty much an equal drive for me to either one, but the drive is nicer out to St. Charles so I've been leaning that way. No more! I've now made my 3rd and final wasted trip out there to St. Charles. Their hours seem spotty to me. I think it's Wednesdays that their hours are shorter (or they're closed all together) so I'll take the responsibility for not checking their hours before heading out... but 2 other times I showed up at their door during their posted business hours to find them closed for a 4-5 days stretch. Maybe I'm just unlucky; everybody's entitled to a vacation, but I'm done making wasted trips.
I like the guy that just bought Elmhurst Winemakers anyway; plus, there's a good barber shop right next door. Kyle at Winemakers always makes me feel welcome, offers me a homebrew while I mill my grain, and always has at least a good, if not great selection of hops and yeast.
Unfortunately he doesn't do bulk specialty grain yet, but he said he's looking at moving to that. Currently you have to buy your specialty grains in 1-lb bags.
Plus, his hours are predictable and reliable!
I haven't checked out Fox Valley yet - might give them a whirl since I work in Geneva...