Well, the highest corn you can get would be George Dickel, which though they call themselves Tennessee whiskey they meet all the legal definitions of bourbon. But I'm not sure that's where I would have you start as it can be polarizing. I would probably say start with the classics. I would recommend starting the middle to bottom shelf and pretty low on proof. Woodford, Four Roses yellow label, Elijah Craig, Maker's Mark, Jim Beam, Wild turkey. Go with stuff that comes in airplane bottle size so there isn't much investment. I don't think you have to start out trying them neat unless you really want to. Mix it with Coke, add ice, add water, whatever makes it most approachable to you. There's no wrong way. For me, most of those classic expressions, though all different, will get you in the sweet spot of quintessential bourbon flavors, your brown sugar, caramel, cinnamon, citrus, cherry, a little bit of oak. To me those flavors are where the appeal of bourbon starts.
Also, while you may not like rye as a stand alone, which I understand as I typically don't either, as an ingredient in bourbon it can be a little different. For example, Wild Turkey advertises their product as "High Rye", but it only makes up 13% of the mash bill, with 12% malted barley and the rest corn. So in that context, you're still dealing with mostly corn. I'm the context of most bourbon mash bills, rye is merely a secondary flavoring, and can really balance the finished product if done correctly.
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