I've never read Sharpe, but the TV series is enjoyable enough.
With the exception of parts of the first one, I don't like the Hornblower series at all. Ioan Gruffudd plays the character well, but they've fucked about with the storylines so much to make it TV-friendly that they've spoiled the plots and wrecked its historical accuracy. The books are absolutely brilliant: the TV version doesn't do them justice.