Think back on your life and when you were able to buy Transformers and not able or you quit. I think the longest run so far in my 30 years of collecting has been from 1989-2000, then 2005-2014.
Considering I've only been collecting for about 5 years, it's never more than a few months for me. Unless, of course, you count childhood "collections"(read: stuff my parents bought me). Then close to 25 years.
Between the end of G1 until Beast Wars, then end of Beast Machines to the first live-action movie. I concentrated mainly on McFarlane Toys (comic/movie series) Star Wars and Gundam in the between times. After the 86 movie, I couldn't stand the new cast and direction, so I ditched until Beast Wars. After I saw Armada and Energon, I decided they weren't for me and skipped them until the live action movie. Been with it ever since.
Dudes don't count periods where you just stopped buying toys altogether; I sincerely doubt at age like, 8 or 10 you sat down and said "okay, this deal of me hardcore collecting figures to bash them together has to stop, they just don't make them like they used to". For me it's right now. Besides two figures I got as gifts, I haven't purchased a single figure since MP Smokescreen in December.
That's actually not far from the truth, though. I greatly disliked the season 3 cast, and had no interest in the toys any more. I told my parents this, and they moved on to buying other things.
Between the mid-1980s and RiD. I saw Optimus and Ultra Magnus in TRU and just snatched them up without even really looking at them. I thought it was some kind of reissue thing going on, and I thought I was finally going to be able to get two of the toys I never could own as a kid. I was halfway to the register before I noticed than Optimus was a fire truck. "Heeeeeeeeeyyyy..." But they looked cool, so I bought them anyway. Then I found the new cartoon on FOX, and I was back in. I stopped watching and collecting during Energon and Cybertron, although I still picked up the odd figure here and there. And I guess I was into collecting old Beast Wars/Machines figures at that point. So I guess that wasn't really a break. Stopped again after that, skipped the entire first two Bay movie lines. Skipped Animated completely as well (what a mistake! Oh well, live and learn). Got back into the toys when DotM came out and have been buying fairly steadily (although not great amounts) since then. So yeah, I guess the biggest hiatus for me was about 1987-2001. 14 years. Wow.
1986-2001... I was roped back in by seeing RID toys and bought a fair amount of RID stuff, a few A/E/C things (worst money ever spent on TFs was on Unicron trilogy crap!) Got back into the full swing of things with Classics and Live Action Movie figs, eventually leading to massive CHUG, Movieverse and Prime/Beast Hunters collections!
In all my years of collecting from G1 up to AoE, my longest hiatus was from the start of the BW TM2 line all the way up to when RID first hit here in the US.
Yea the Uni Trilogy sucked me in as well. Although I do love my Armada Starscream, Energon Starscream, and Cybertron Starscream as well as Nemesis Prime they were the few in the far between.
I stopped for a bit around the end of Energon, and didn't pick up heavily again until last summer. Just bought the random few figures in between, and lost track of the fandom a little as well aside from watching the Bay-verse movies, and playing WfC. Missed watching/collecting Cybertron, Animated, and the first half or so of Prime. Picked back up after however many years that was, and have been loving it ever since. In between, collected video game collector's editions, and Halo figures, so I didn't stop collecting, just lost Transformers for some reason. Not really sure why though.
My longest hiatus was from 1986 to 2006. The movie up to the launch of Classics, basically. 20 years. Yowza.
'88 - '08. My last TF from childhood was probably a Pretender. My interest in TFs really dwindled within a year after the cartoon ended and I moved on to Ghostbusters, Dino Riders, and/or TMNT. Twenty years later, my wife bought me premium deluxe movie Bumblebee as a joke to cheer me up during a down time and I fell in love all over again. I wasn't even a toy collector, but was blown away by how far TF toys had come in 20 years. My wife had no idea what she started that day and has probably regretted it to one degree or another ever since!
Started in '89 an went til '05 or so. First break lasted about a year or so. Didn't pick up TF's again until Universe 2.0 so yeah I think that was the longest. After that I think the longest may have been 8 months or so.
Cybertron to Prime. I picked up the odd figure here or there, but I just recently got back to hard core collecting.
Stopped buying after the end of G1 cartoon. I picked up one TF (Powermaster OP) between that time and seeing RiD Optimus Prime (the big ass fire truck) @2001. That figure kicked ass. I got a few of the RiD figures, but I didn't like the cartoon at the time, so I was really spotty during A/E/C. I didn't watch the cartoons, and I only picked up figures that interested me visually or that homaged G1. Classics turned me into a "buy everything that gets released" sort of collector. So yeah...
I stopped briefly in my first two years of college, so missed out on the Classics and beginning Universe to 2.0. I think the first figure I bought from that line was Galvatron when I started again.
