I would put Aldous Huxley in there, too, and certainly PG Wodehouse - great writers don't have to be serious writers, and Wodehouse was a considerable craftsman. And I'm glad you say 'writer' not novelist, because Orwell was primarily a journalist and IME (not universally shared, granted) the recent BBC series from his writings have diminished not enhanced his standing.
Orwell is a writer who I can enjoy reading regardless of what he's writing about. (Julian Barnes likewise, but I don't know that he comes under the heading "classic" yet.) I love Orwell's essays - he even writes beautifully about food - his essays on making the perfect cup of tea and Christmas pudding are wonderful.
The only Huxley I've read is Brave New World, which is a must-read for anyone. I should try more of his stuff.
And I totally adore PG Wodehouse. I've been collecting the gorgeous Everyman edition, of which about four or five volumes have been published every year since 2004, I think. Lovely hardbacks on quality paper with beautiful cover illustrations. Proper collectors' items. The thing is, I've been discovering that because Wodehouse was so prolific, not all his stuff was up to snuff. Especially with the later works, from about 1960 onwards, you really get a feeling that he's just treading water and is a writer whose time has passed. On the other hand, I've also been discovering a lot of the lesser-known early works for the first time, some of which are just wonderful.
If I had to recommend one Wodehouse book above all others, I'd go for Leave It To Psmith. My favourite Wodehouse character (Psmith) in my favourite Wodehouse setting (Blandings). It's even funnier than Scoop. I don't think any writer makes me laugh out loud as often as Wodehouse. (Psmith, Journalist is one of the early works I've not read until recently. It is a rare example of Wodehouse showing an overt interest in politics, but is still just as funny as you'd expect.)
And even though I hate golf, I love Wodehouse's golf stories, so I'd recommend those too - The Heart Of A Goof is a fine collection.
Huxley is an interesting contrast with Waugh. Ten years older and with a similar background and education, but from a long line of rationalists and scientists and to my mind a much more modern writer.
Yes, I'd agree with your assessment, though I think Waugh at his best is timeless - he's just a master wordsmith. You've definitely made me want to read more Huxley though!
d.