I watched the show before reading the books, but I absolutely adore both. As others have said, the casting of the two main characters is perfect, though i wish Fry could've had more of a chance to show off.
There are a few notable differences between the two mediums, none of which hamper the viewer/reader's pleasure any. In the show, for instance, Jeeves seemed to be more warm-hearted than in the books, where he seemed to me to be more of an untouchable impressive figure, almost cruel at times to Bertie, though always pulling him out of trouble in the end. Fry's portrayal was preferable to the books' character, for me, because I enjoyed the more casual relationship. In the books, Jeeves was almost a father figure, not nearly so close.
One reason i enjoy the show so much is the way it ignores pressing world issues. The prohibition is in full swing over in America, but that is only referenced in one episode. The depression is about to hit, and the entire world is going to feel it, perhaps even Bertie. I've always found this fact to make my viewing all the more interesting, because Bertie and his friends take their wealth so casually. The books are written from Bertie's perspective, and as it's plausible that he would ignore socialism and other radical reform movements, economic disputes, prohibition, and other strife synonymous with the 20s, then so would the show. It's a wonderful departure from reality, into a world where your only worry is how to weasel out of unwanted engagements to less-than-admirable girls, or how to avoid your overbearing aunt.
It's all of these things that really put the Wodehouse stories and their subsequent television adaptations close to my heart, but it's the lovable characters and the flawless portrayal of them by each respective actor that keeps me drawn to watching this show over and over again.
