Oh I misread the OP. With all the attention on the Sgt Pepper Giles Martin remix, that was the one I thought about - the set does contain both. But if you're going 'all mono' or 'all stereo' that's a bigger choice.
From what one reads, the earlier steros from the Martin/Abbey Road days were pretty primitive, and that's certainly what I get from my stereo copy of Abbey Road and Sgt Pepper - just 'bung all the drums over there in that corner' and 'let's stick George over to one side'. I'm tempted by the Giles Martin Pepper remix as that's supposed to be more subtle in the modern styl-ee. So I personally am tempted to hear the monos as they're likely less distracting.
By 'The Beatles' (White Album) the stereo is more grown up and I can listen to that without wondering WTF is going on, or doing an impression of a tennis crowd when the guitar comes in.
Just a personal view as are all things audio - buying music or kit by reading about it is difficult! I guess as @AntAxon suggests, a mono button on the amp would take away the conundrum as you could listen to the stereo versions without the 'kid with a new toy' stereo effects.