From 1967 to 1983, the engine that ruled Formula One was the Cosworth DFV. It was compact, powerful, reliable, and cheap. Any customer could buy one, mate it to a Hewland and have a competitive chance. It won ten constuctor's championships and twelve driver's championships. It produced ~166 hp/L in the 70s and rarely broke down.
It is surprisingly easy to draw parallels between this engine and the LS series engines. Compact, cheap, reliable, powerful, ubiquitous. The LS series (now being superseded by the LTx series) may be the greatest engine series ever.
I used the hate the LS engines. I thought the engine was outdated. I thought the swaps were uncreative. I thought that it was ruining car culture by making everything the same. I like flat plane V8s. I think Ford is the greatest automotive company in the history of the automobile. I like DOHC engines. I like independent throttle bodies. But, it doesn't matter what I like. The LSx engine is the greatest engine ever.
I have a thing for weird swaps. I like completely custom cars. That's why I could never like LS3s and LS1s powering everything. It isn't unique. It isn't special. As I become more of a boring adult, though, it makes more sense. The engine will fit in most engine bays that DOHC V8s (and even V6s) won't. It is comparatively cheap. Cosworth Duratecs are around $10000. This engine is awesome. 2.3 normally aspirated liters making 280 horsepower. From a British firm that got its start building F1 engines for Colin Chapman. On the other hand you can get a V8 for $2-3000 less making more power, more torque, and with loads of aftermarket parts. You can fit it in nearly every engine bay without structure-ruining modifications. You can go over to Pep-Boys for parts, and you can use the first 40 Google hits for help on pretty much anything.
The tunability of these engines is off the charts. 500 reliable horsepower is no problem. 700 horsepower? Not terribly hard. 1000? No problem. Obviously, as the engine undergoes more stress it will be less reliable, but those power figures are easy to achieve and replacement parts are plentiful. They are a cheap, reliable, flat torque curve. I could buy a 707hp Hellcat. Or I could buy a C5 Corvette, a supercharger or turbo setup, have 708hp, and some change left over.
I say all these things make the LS series engine the best in the world. But any engine can be. Automakers just need to make their engines available in crate form for pretty cheap. Subaru could be making the greatest engine in the world right now. If I could buy a brand new 2.0L turbo flat4, and put it into the engineless Fox body on Craigslist (something else compact, ubiquitos, and cheap), it would be the greatest engine in the world. If the Ford 3.5 Eco-boost could fit in an NA Miata and have hundreds of forum threads on how to do it painlessly, it would be the greatest engine in the world. If the 8.3L Viper V10 was readily available for all the Icelander's crazy dune-buggies, it would be the greatest engine in the world. If someone could put the 5.0L Jag V8, a BMW I6, an AMG V12, or a Lexus V8 into the track day project that they started but has stalled, they would be the greatest engines in the world. If I could put the I3 turbo from a Fiesta in some wird project that I haven't actually finished thinking up, it would be the greatest engine the world.
I don't want to hunt junkyards or shady websites for an engine when I can finally build my pipe-dream. I want to buy a clean engine, buy some accessories from Edelbrock, and plug it in. I want to have the option of it being transverse or longitudinal. I don't want to worry about it grenading itself. I want to have a predictable torque curve. I want it to fit in a Miata, a Fiero, and a Corvette.
The LS series isn't the greatest engine because it's the greatest engine. It's the greatest engine because, it is compact, cheap, reliable, powerful, and ubiquitous. Don't criticize the weird stuff on NPOCP for the builder settling for an LS, criticize every other manufacturer for not making the right engine for the job.