Centennial(DolgoXWealthy) is tops here. 2" red-striped yellow fruits with sweet, crisp yellow flesh.
Kerr(DolgoXHaralson) also good; slightly smaller red fruits, crisp, tart white flesh, with a musky wine undertone.
Chestnut and Wickson crabs consistently get rave reviews in fruit-tasting comparisons, but I've not fruited either here.
Whitney gets mixed reviews - and there are at least two different cultivars circulating in the nursery trade as 'Whitney'.

I was warned off the red-fleshed crabs, years ago, by a long-time orchardist/nurseryman, who told me they'd be 'crap' here(just north of the TN line; I planted them anyway) - and he was mostly correct. They may do OK for you in N.IL, however. In my orchard, only Almata is worth eating; others(Geneva, Giant Russian, Winter Red Flesh) are only good for jelly production.

So long as you purchase your crabs on rootstock suitable for your site and climate, any of the crabs above should be fully winter-hardy.
The red-fleshed selections all have pink blossoms and red/purple-tinted leaves. All the others mentioned above have white blossom, so far as I'm aware.

Some of the 'ornamental' crabs, such as Callaway, Evereste, and even the old standard Dolgo, are pretty good eating - just small fruit size.

Not sure if you can get this Alberta Crab Apple...Trailman, still good for zone 4 or colder. This is a WOW crab! Crunchy, sweet, lots of juice, great flavor, one of the best for juicing.

Flower is mostly white...
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A very strange apple, it turns dark...then light in color when ripe.
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Whitney gets good reviews grown here in Western Montana; I haven't tried it.

Thanks for the suggestions! This early spring we are having here has taken us by surprise, but also given us a lot of extra time to get planting!

Konrad - Thanks to your posts on Trailman, I am really looking forward to trying this one out. I'm assuming that the yellowing("light in color when ripe") is probably the brix factor kicking in just before proper harvest window. Have got scions on the way from Fedco for a very soon upcoming grafting operation. Those folks told me one of their absolute faves as well. Hopefully can weight in myself in a few years on this one. Sure looks and sounds yummy to me. Thanks again for the heads up.

Thanks, Konrad.
I'd forgotten about Trailman - have a young tree of it, just a whip, no fruit yet.
Your photos of Trailman look very much like the ripe fruits of Centennial.

Here in the link from our annual fruit festival, about 13 plates
are all mine, most with hail damage.
Also have Trailman and Chestnut, someone has Centennial..klick right or left,
looks very small.
Chestnut is not bad...kind of a nutty flavour but on the dry side.
Trailman is just loaded with juice,...just like a pear, it sinks to the bottom when put into water, just like pears do. I havent' seen another apple do this.

Here is a link that might be useful: Devonian Garden Fruit Grower Festival, Sept 2011