The Delta Cycle Michaelangelo and Saris Bike Bunk are both affordable, minimalist gravity racks that simply lean against the wall. They both have adjustable arms which enable them to accommodate sloping frames. Feedback Sports and Delta Cycle both make tension racks, which have a minimal footprint and don’t attach to the wall, they stand with tension between the floor and the ceiling. These are very easy to install and the soft rubber arms on Feedback Sports’ Velo Column help protect your bike’s paint. If design is your primary concern, the Saris the Hottie 2-bike stand is a good bet.