I'm going to see if I can find some good local offers for the 18-135 IS STM lens, I'm currently looking at a Sigma 18-200 F3.5-6.3 DC OS HSM, do you by any chance have any experience with that one? I've found one nearby for a great price and it seems pretty solid to me. (Which again is purely based on impressions gained from youtube reviews)
No, I never had interest in mega-zooms. Check some reviews and make up your mind based on them. From my experience: looking for a good lens might take a while. For me it was easy to decide which body to take but I'm picky about lenses. You need to try them out, to know if you like them. And this means either borrowing or buying. What matters are parameters which you won't find in spec.
My history looked like this:
Canon EF-S 18-55mm f/3.5-5.6 IS -> kit lens which I bought with my 450D in 2008; I've used it for a couple of years but since beginning the sharpness was disappointing
Canon EF 50mm f/1.8 II -> amazing sharpness and contrast compared to 18-55 IS but my 450D suffered backfocus, so I used it in manual AF mode in LV only, I liked this lens a lot for its image quality but didn't like the bokeh and miserable AF performance with my body
Canon EF-S 10-22mm f/3.5-4.6 USM -> very good image quality, quick AF, very well brightness (aperture) for this focal length range, extremely useful lens; I loved it from the first moment and it's still one of my favorites; a must on my holidays
Tamron 28-75mm f/2.8 XR Di LD Aspherical -> the idea was to replace the kit but it was only a half-success; image quality was great, on par with 50mm f/1.8 II, nice bokeh but AF was a real disaster which got only a bit better after calibration of the lens at Tamron's service and 450D at Canon's service, AF is also terribly slow and I ended up toggling all the time between 10-22 and 28-75 as I found out the focal range between ~18 and ~30 was for me mostly in use; would be a nice lens if the AF was better but because of this reason I don't use it anymore (inaccuracy depends on the focusing distance, so even AFMA doesn't help)
Canon EF-S 18-55mm f/3.5-5.6 IS STM -> extremely sharp and good quality for the price; I use it for videos due to IS, non-audible AF, non-audible IS and no "pumping effect" when changing focus (I'm just filming my daughter and document some holidays-memories, I'm not a video guy so it's my choice)
Canon EF-S 17-55 f/2.8 IS USM -> my actual standard lens; fantanstic image quality, extremely good and precise AF, good IS, constant f/2.8 in whole focal length range! The only real disadvantages: it moves to 55mm position when carried in a hand or on a sling which is irritating... there is no lock of the zoom ring like the Tamron has. And unfortunately the IS and AF are audible so not that good for videos with build-in microphone.
Canon EF-S 24mm f/2.8 STM -> I liked the idea of a pancake but actually I hardly ever use it; I pack it into my bag only when it's full of portrait lenses and I take it "just in case I need something wider" as it's very small and light; otherwise pretty nice quality but very slow and funny noisy AF; the initial idea was to use it as an only lens when having to limit the weight on a trip but in such cases I take the EOS M with 2 lenses which is just a more versatile set
Canon EF 50mm f/1.4 USM -> I wanted to replace my f/1.8 II but don't like it at all with its horrible random AF, awful CA, blurriness up to f/2.2 (but gets super sharp afterwards), awful bokeh, fragile mechanics; it's a 1990s construction and should stay in that times... I'll get rid of it soon
Canon EF 85mm f/1.8 USM -> fantastic image quality, I love the bokeh and colors since the first minutes; one of my favorite lenses but I use it for portraits only
Canon EF-S 55-250mm f/4-5.6 IS STM -> I rarely use such "long" lenses but few times I've missed one, so decided for an inexpensive but sharp one; dark and pretty slow AF but great otherwise and very lightweight, what is important for me since it's not my primary lens and the more important ones are too heavy already; great value for money
Sigma 50mm f/1.4 DG HSM Art -> my actually favorite lens; great, consistent, fast AF, extreme sharpness even fully opened, no CA, awesome bokeh; I love using it and seeing the results afterwards

My best lens ever but you can feel it in your back

Canon EF-S 10-18mm f/4.5-5.6 IS STM -> newly purchased, probably will replace my 10-22 as it's sharper, smaller and has IS; handheld exposures up to 1s are killer!; due to IS can be used as a pretty wide lens for filming in 3x zoom mode (so no line skipping and aliasing on 70D); but I'm not sure yet it will really replace 10-22 as I have to start using it first to tell
Sigma 18-35mm f/1.8 DC HSM Art -> this I'll buy next for the next holidays in Lappland, hoping for better night photos of polar lights than last times