I don’t know about other designers, whether they wrestle with visual design, or the overal information architecture, but the hardest thing for me to decide on is the typography. I prefer to use serif fonts, particularly Georgia and Palatino, but lately I have begun to use the Arial and Helvetica fonts more and more. Frankly it IS a really difficult decision, because some fonts have a greater impact on the viewer. Should you use different fonts for <h?> tags? Should you use a slightly different font to accentuate something? I have seen some designers use a separate font for blockquote, for example, or the old favorite using <cite> or <code> and the old ubiquitous machine fonts (very blocky, remember green letters on a dark green screen?)