I dearly love the Albert Nozaki design for the war machines in George Pal's 1953 The War of the Worlds. They are smooth, elegant, still unique, and (coupled with the sound design) utterly menacing.
The 1980s TV show had many flaws, but whenever they threw in one of these babies (which were sort of the Ultimate Menace, given invulnerable they were), it was magic.
George Pal originally envisioned using classic Wellsean tripods, but it was more difficult to portray and military advisers said mechanical tripods would be vulnerable to attack (see: The Empire Strikes Back for the vulnerability of quadripods, for example).
The "easy" answer, magnetic "tripod" legs holding the war machines up (which is why they don't actually "fly"). These are visible in a few scenes, but the original effect was deemed too much of a fire hazard to sustain. Still, even when the magnetic "legs" are not visible, the ground effect is often shown.
The sound effects (https://www.youtube.com/watch?v=pS1QapooZrM) are a big part of it, too (and sufficiently cool that many of them became stock).
Cool stuff.
Alas, the original Martian War Machine props from the movie were actually made out of copper, and were donated to a Boy Scout metals drive. Almost as prosaic an end as that suffered by the Martians …
Looks to me a late 90s and Early 2000s CGI.