\textrm
(roman),
textit
(italic), \textsc
(SMALL
CAPS), \emph
(emphasis, but note that if you use
emph within emphasized text, you will get roman text),
\textsl
(slanting), \texttt
(teletype), \textbf
(boldface),
\textsf
(sans serif). As long as there's no conflict, these
commands can be combined so that, for instance, this is bold sans
serif can be produced by \textsf{\textbf{this is bold sans
serif}}
.