Originally Posted by RandyM
Yes, there are crossovers, but plotwise they don't amount to much. You'll be fine just watching all of a Buffy season or all of an Angel season. I think that keeps the rhythm better anyway.
While this may be true for some of the episodes, the two double parters mentioned above really need to be watched first. If he did want to watch the whole season in one go, he should at least watch the entire season of Buffy first, then Angel. If I remember correctly, all of the crossovers in the first season of Angel started over on Buffy.
The only one I'm unsure about is the Buffy episode "The Yoko Factor"...