LoTR's multiballs are good (I don't care for the machine in all ways, but I've got to give them credit for having three very different multiballs).
Not sure multiball is something I'd comment on about Spider Man. SM's multiballs are typical. The start is typical shoot light lock, shoot lock, repeat 2 more times to start for one of them, and shoot the Doc repeatedly for the other one. The "holding the ball" bit on the Doc Ock multiballs are cool, but one rarely gets to the later Doc Ock multiballs anyway... But the jackpot animation is uninspiring, as is the size of the jackpots... SM is a good game, the multiballs are fun, and the model for the modes is a nice twist on the "1-shot-per-mode" paradigm. Maybe if I was better at the Doc Ock shot, i'd appreciate it more.
TAF certainly deserves mention - the rules for the multiballs are pretty vanilla, but the introduction sequence and to a lesser extent jackpot award sound effects are among the best in pinball.
TZ deserves mention, for having just about the loudest jackpot animation ever, and for the change in music post jackpot. But again, the rules are standard Lawlor multiball rules (big points from the jackpot, no points for other shots, jackpot shot made with upper flipper, need to do something to relight) - good rules, but not something to call home about.
BSD is an interesting one for this list - mainly because multiball is ALL THE GAME IS. All about stacking multiballs and collecting triple super jackpots. A "Do one thing and do it well" - it's certainly notable in the emphasis it puts on multiball. I haven't played it enough to really come to a judgement on it, but more than any other game, it's all about the multiball.
I also feel like F14 is kinda notable here - it's up there with TAF on the multiball introduction sequence (with the topper illuminating the whole arcade), and it's one of the earliest games with a 4-ball multiball. However, that's the only multiball on the game, and the PF didn't have enough room on it for many shots due to the aircraft carrier and the thing in the center, so i don't think it's a contender for the title of best multiball game.