I’m a big fan of SoundCore products. I’m currently using the Space Q45 which replaced my pair of Life Q30s which I used the hell out of. IMO the Life Q30s have slightly richer sound quality despite being quite a bit cheaper than the Q45s, but all of their over ear headphone are super super comfortable and have good noise cancellation.
Thank you for pointing out that the Soundcore over-ear headphones are good. I've wanted to try this brand again because of the price point.
I've tried two different versions of the Soundcore in-ear noise cancelling buds and none of them did anything remarkable, IMO. I always went back to my Bose over-ear NC headphones.
I wonder if that's just a consequence of earplugs not being as good as earmuffs in general, though.
Also buy used, I just got a pair of WH-1000XM3s that still have the original case for $100. The ANC is so much better than any new $100 headphones and the battery life is still great.
In the cheaper price point, IEMs are probably the way to go for noise isolation. If you can get ear tips with a good seal, then the passive noise isolation should be good enough. I'd recommend something like the kz zsn pro (~$20) or the kiwiears cadenza (~$30), along with comply foam tips (~$15) for a perfect seal into your ear. If you have smaller ears like me, then kz IEMs can be a bit uncomfortable, so keep that in mind. If your budget stretches further, then you can try Etymotic ER2SE IEMs (~$100), which have triple flange tips that really plug your ears deep, but I definitely don't find them comfy enough for long sessions.
If your device doesn't have a headphone jack, an Apple USB C dongle (~$10) is plenty good enough for any IEMs, or you could get a Bluetooth DAC from Fiio starting at around $40 (for the longest time I had one doing double duty for my headphones and for Bluetooth audio in my car).