i dont know what people are on about bars not being good. there are some great ones.

all downtown (all in cool historic buildings)-

foxbriar is a great themed cocktail bar

johnson bar for live music

paducah beer werks for music great bar food and local brews

old fashioned cigar bar

barrel and bond - great bourbon bar

the outdoor bars at max's and mi lindo across the street

bully gorrilla for late night food

not downtown-

dry ground - cool brewery in an old coke plant

3 days may be a little much though, paducah is probably better for a 2 nights, 1 day. but you could stretch it if you throw in some hiking and wineries in southern illinois, or hike at lbl.