Will a tilt shift lens solve my "crooked building" shots?

Not only do you need the inclination for perspective correction shift is relevant here. There are some switching adapter offered to switch between a DSLR case and a medium format lens would also help; Note, however, that medium format lenses have relatively long focal lengths – eg. 45mm is already ultra wide for the medium format.

One way to visually get a better perspective without special equipment is to use a wider angle Lens. Hold the camera so that the lens is oriented horizontally (for example, in portrait orientation) so that the building fills the upper half of the frame, and take the picture harvest later. In any case, the shift lens works anyway. Only now you waste about half of your megapixels, because the image circle of a lens without shift is smaller and firmer. Here is a picture that used this method (except for cropping, since I liked the extra patch):

Tallinn Town Hall

Which method of correcting the perspective is also used, a slightly leaned Buildings will look more natural in photos than those with perfectly parallel lines, at least as long as we do not learn to float in the air all day long. This tip does not apply to photos intended for an architectural magazine.