I have a Willy's in the garage and I've obviously got a TJ. I've been around some JKs and driven some YJs (have one but it can't drive) and my granddad drove a CJ-5 throughout my childhood.
The TJ is my favorite and the most reliable. The Willy's is always breaking and needs to be towed for longer trips or for repair (it's also not driven enough, so the unsealed gas tank and Carb, don't mix well). JKs and newer just look like crossover SUVs IMO. They're fine, but the only draw for me to a new Jeep would be the ECO diesel, as Jeeps should be standard with a diesel and option for a high HP V8 IMO. Unfortunately new diesels are completely F'ed, so you're actually better doing a swap IMO for diesel, but that's obviously a can of worms.
When it's working, the Willy's is the most fun. The wife and I would love to have a Willy's pickup, but we'll probably not go that route due to practicality.
The YJs are super nice too, but very similar to TJs and the TJ is a little more comfortable and the gas cap isn't weird.
If one wanted the most reliable and simple Jeep, I would personally go for a TJ with a mechanically injected diesel with manual transmission. For practicality and typical reliability, common rails tend to have less problems, but they tend to be newer too and if you had a problem with a wire or ECU, you might go into limp mode. I look at this just like our tractors. Gas tractors always seem to break down or a wire gets pulled off and the diesels start right up as long as the battery is good (we don't see extreme cold, but we do have 2 tractors that literally have the exact same block but one is gas and the other diesel). With the exact same battery and newly rebuilt carb and ignition system the gas is much harder to start than the diesel, which has more hours and less maintenance done. Though the gas has more HP it can't do the work of the diesel. I really don't know of a positive over the diesel version. I've been around trucks with similar experiences, except for trucks the diesel version is MUCH MORE expensive.
Another reason I do find the TJ the best of all worlds, because the problems are known, as are the fixes. My TJ is kind of based on taking a lot of tried and true and making something that's extremely capable, reliable, and versatile. The only wrench in the system, is me as a mechanic and electrician. Also I could certainly side with someone that suggested using something like a small block for the engine, since they're extremely robust and parts are incredibly common, but at that point I'd stick with the inline 4.0 and just ensure my gear ratios were a bit on the high side (numerically). Though I can see the draw, I don't trust forced induction on gas engines for these applications, just too many failure points for going to places with poor cell service.
Really the only problems I have found with a TJ are the gear ratios, transfer case, preference for bigger tires (and all that entails), lack of a practical diesel option in the US, brakes, noise, and probably a few more I am forgetting. I think Mike (
https://wranglertjforum.com/threads/vm-2-8-turbo-diesel-frame-up-tj-build.17369/) is building a TJ the way it SHOULD have been built from the factory. Personally I found the Cummins, to just be a faster swap option, hence my R2.8 conversion. However, I should have bought another TJ and gone a little slower in my build, but I would have spent A LOT more money at that time, rather than over time.
For all the problems, there's some very solid and known fixes with the TJs and most fixes aren't that difficult and can be implemented over time. A full tub off rebuild isn't a crazy task or price compared to buying a new JL Rubicon. At the same time a Willy's or CJ can be completely customized as well, but I do think the TJ has more to start with, for some style and function.
An obvious draw for the JK and JL are probably the 4 door unlimited models. To each their own, but I'd rather rebuild a mid-2000s 3/4 or 1 ton diesel truck, but I do have to tow occasionally, hence my major bias. But my 3/4 ton from the factory gets hung up less than my TJ, until it simply wouldn't fit and it would get better MPG than the TJ while towing the TJ. When the truck does get hung up, it's 3x harder than the TJ to recover. I'd probably even get a FJ before I got a new 4 door unlimited.