Just started doing a re-watch, right from the beginning (of my DVD collection).
Since I have "The Beginnings" boxset, that's right at the start. Watched An Unearthly Child yesterday but skipped the three cavemen episodes and went to the seven-part Daleks story. Half way through that now.
Oh don't do that! Yes, a few countries got it like that in the mid-1960s, but that three parter is a good solid story in its own right (the contrast between Za's superstitious reaction to the TARDIS crew "They are from god, or are demons", and Kal's rational one "They are from a more advanced tribe over the mountains, and we need to know what they know" is a bit of a philosophical mainstay for the series as a whole). And it's important in the character development of the regular cast... even referred back to in the big arguments in the third story!
Seriously... the dawn of time episodes are worth seeing... they're an odd halfway house between the early SF stories, and the historicals, as they're a bit of both. It's not three wasted episodes (that's The Keys of Marinus... for six episodes). Personally I'd put them about 3rd or 4th of the seven first season stories that still exist in some form on video. So watch them yourself and see what you think.