I'm not familiar with the P.G. Wodehouse work that was the basis for this series. Sometimes though, not being familiar with the written material can help you enjoy the TV-series or movie better. I'm not certain if it helps here but i did in fact find this very entertaining.
I remember watching this series every Saturday on TV for quite a long time. And my view on both Hugh Laurie and Stephen Fry is still marked by this. Both are in my opinion perfect in their parts. Laurie with his rather silly and foppish British looks, his accent and his voice. And of course Stephen Fry who looks every bit the aristocratic manservant.
The stories presented are usually both silly and with little reference to reality. But they are entertaining nevertheless, and why watch something like this if not to be entertained? The silly aristocrat and his wise servant is a classic theme, and rarely is it done better than here.