The worst part of Champaign-Urbana is campustown. Downtown Champaign is the best section of C-U. Within a 3 block radius you have tons of great choices for dining, drinking, music, shopping, etc. If you want good shopping, look for The Furniture Lounge, Homeworks, Old Main Bookshop, Jane Adams Bookshop, Carrie's, Circles, Rebecca's, Walnut Street Tea Company, and the new record shop opening in the One Main building. If you want pubs/bars check out Mike & Molly's (great beer selection, best laid back atmosphere, best beer garden), Esquire(good bar/grillfood), The Blind Pig (great beer selection, hand pulls, no TVs!), Brass Rail (townie bar to the core), Cowboy Monkey (live music), Jupiters (pizza and pool). Go to Sam's Cafe for breakfast/lunch (best french toast ever!) and Cafe Kopi for coffee drinks and good local art. Nice dinner? Radio Maria is a must! Great Impasta and Peking Garden are also good choices.
Downtown Champaign also boasts annual events such as Artists Against Aids (April 22-24) in the old Gallery building on Church & Neil, art gallery event with tons of local artists' work for sale, with 50% or more of the proceeds going to GCAP. Roger Ebert's Overlooked Film Festival (also in April) at the VIrginia Theatre. Virginia Theatre also has screenings throughout the year of classics to 80s fun flicks. New Art theatre has great art, independant & foreign films.
Downtown Champaign has all of the best community events arts and culture.