Honestly I think it depends on what you want to shoot, but maybe the 24-105 f/4.0 L. But you should check it out in person first because maybe it’s heavier than you want in a general walk about lens.
what do you want to do with your camera? landscape, nature,wildlife, studio work like portraits or street photography or etc etc
Or just a simple basic allround setup?
Some already mentioned the 24-240 that's a great lens for start with, delivers good results and optically it can get close to the 24-105L
But just as important is this: What's jour budget? Some RF lenses are not cheap Like the L series lenses.
The RF 24-105L is also a nice one to use but it's pricetag is above the 24-240.
And also the RF 16mm and the RF 35mm macro are nice lenses to use and they are not that expensive.
As an RP owner I am sometimes tempted by the 24-240, have all the range in one lens, with good quality. But then I am put off by the weight and size, compared to my M6II and 18-150 combo, despite the importance of that 24-29mm range I don’t have.
I like a smaller kit when going out and about for my landscape / travel / street photography, that’s why I think the R8 with the 24-105 STM could be a sweet spot for me in terms of versatility and size/weight in a full frame kit, with the tiny 16mm and 50mm in the pocket for wider photos or portraits with blurred backgrounds.
My better half loves the combo RP and 24-240, (she did use a 6DII and 24-105L before that) And often only the RF16mm and RF35mm macro will be packed in her backpack with the RP and 24-240
When we got the RP at the end of 2019, they were kitting it with the 24-240 for $1,499. And a Pixma Pro-10 Printer for $350 off and a $350 mail in rebate (so free). I used the rebate for a deal on the RF 35 f/1.8. 😁
…..Fondly remembering the salad days, pre-pandemic. 😂….
When I moved to the R6II, I bought it body only. I sold the RP. I kept the 24-240 as my “kit” for the R6II. Honestly, I think they’d do well to kit the 24-240 with a couple bodies again.
As others have mention it all depends on your personal applications. I live my RP with the 35mm IS f1.8 macro, it is am awesome all-arounder, focus at 15cm, IS, sharp wide open, compact and affordable. 35mm in full frame gives you lots of flexibility.
I use the 24-240 with my R6, and find it very comfortable and well balanced when walking with it. I have a Peak Design cuff and let the camera hang from my fingers. I have posted sample pictures here.
When I take my bag, I also carry the RF16 or RF35 f/1.8, which I also find excellent.
I think that the R8 pairs very nicely with the RF 24-105mm/4.0-7.1 STM and the RF 35mm/1.8. Both are quite compact and really light set-ups which I like to take with me if weight and size matter.
I had the RF 24-105 STM before when I used it on a RP, but when I sold the RP (and switched to a R5) I also sold this lens. When I aquired the R8 I soon missed a light/compact medium range zoom lens so I bought a cheap, presumably never-used, 24-105 STM taken from a kit. So far, I'm happy with it and find that IQ is more than sufficient for me.
I have this one on my radar as well since I find the 24-105L a little too heavy for more casual travel photography. And given the small difference in size and price I find it hard to justify buying the 24-50 with its (very) limited zoom range.