[MDixon]

Ok, back under consideration. I'm easily persuaded at times.

[ScallyWag]

I have 3 plastic water carrier/dispensers (came with spigots) that are 2.8gal each, cost me about $3 each at Walmart, and two more "sun tea / iced tea" plastic dispensers, 3.0gal each, cost me $4 each at Kroger.  I've been using them for nearly 4 years, never a contamination.  Also, I no longer use air locks, I just leave the plastic screw-on lids just barely unscrewed enough to to permit off-gassing when the pressure pushes the lid up - same kind of thing that my Mr. Beer kit's LBK does when it's lid is screwed on all the way.  (The Mr. Beer kit was the gift from my daughter that got me started in this hobby; I still use that LBK occasionally too.)

So I have 6 FVs of 2.5 to 3.0 gallons that I put about 2 gallons of wort in, so that I can split a big batch of wort up among different yeasts.

I'm uber-cheap, but I love the beer that comes out, so win-win.

[Visor]

    I guess I'm the wild card, I use [mostly] the 7.9 G Fast Ferments. There are several things about them I like, but I do have frequent issues with them and cuss them unmercifully. First positives, no racking to another vessel for anything, unless I'm barrel aging a batch. I cold crash in and bottle directly from the FV. I harvest yeast at any point and as many times per batch as I want, and the recent introduction of Mason jar adaptors was a huge improvement over the original harvest ball, and it gives me the ability to choose a jar size ranging from ~1/2 cup clear up to a quart. I do purge the replacement jars with CO2 before attaching them and opening the valve so as not to introduce a bunch of air to the vessel. They are still only about $100 [I think], and they are lightweight.
   On the negative side, the lid O-rings do sometimes fall out at inopportune times and places. More than once, I have had the valve core get stuck to the jar adaptor when removing it, which makes for one hell of a mess, and the thermometer that comes with the FV is pretty worthless, I just plug the thermowell and tape an inexpensive indoor/outdoor thermometer to the outside of the FV with a pad of insulation over that. I currently have 5 of the 7.9 G FFs but one was retired early because the lids never would seal, I think the top lip of the vessel was mis-molded, it has since been cannibalized down to just a shell.
   I do have a couple of the small Fast Ferments but can't recommend them, they're just a total PITA, nothing but problems. I also have a few 5G buckets that I installed valves on and have used them a few times, but there really is nothing about buckets that I like, they only get used when every other vessel is in use.
   Over the 8 years I've been using the FFs I have developed/built tools and gear to address the issues I've had with them. I suspect any other brand of FVs would have their own particular shortcomings that would need to be addressed. I recently bought the 5th one, before I did though, I looked again at all the options, but couldn't find anything that looked to be a better choice, sometimes better the devil you know than the devil you don't know.
   

[Paul Bern]

I have  5 gal and 6.5 gal Big Mouth Bubblers. Very light, durable (5+ years old and still good) and easy to clean (I can get my hand all the way to the bottom. I use the 6.5 as a fermenter and the 5 as a secondary if I lager. Definitely get the carrying straps.

[CounterPressure]

Years ago I went to a local container supplier (sells barrels for use commercially) and at the time they had a building full of Pharmaceutical containers that were 15G each, dark blue with black full diameter lids and steel band clamps. Each had been a 1 time use item, sterile and clean.  I bought 3 of them to haul water in because my home well water at the time was not good for brewing, but my water at work was great.  I load them in the pickup with a forklift after filling, and each one makes a 10 gal AG batch with about a quart or 2 left over.  They're easy to move around with a hand truck. Not so fun lifting off the truck when full to the brim.

I put a grommet in one lid for an airlock and have used that as a fermenter very often, making some of my all time favorite batches in it.  The others have never been used for anything but water.  Often I'll empty that one for a brew and sanitize it and refill with wort when the batch is done.  I wish now I'd bought about 6 of them because at the time I think I paid $10 or $15 each.  They sell other barrels, but often the lids are small bungs or non-removable, or without good seals, and I really like the band-clamp lids with the silicone seals these have. 

If you have a container company local, perhaps check them out for alternatives to some of the VERY expensive name-brand buckets. 

[Drewch]

More than once, I have had the valve core get stuck to the jar adaptor when removing it, which makes for one hell of a mess...

Same.  I got fed up with their valves and passed my Fast Ferments on to a home winemaker.  (They're also quite tall for the volume they hold.)