Also, on this... there's a lot of fanKFADs. Like, a
lot. I can link some of them if you like!
Mashup Week Classic was running at around the same time as KFAD2, and was somewhat based on both that and the original KFAD, making it one of the earlier fan KFADs. It's notable for really running with the boss formula, many of which have since been made into playable characters in the sequel. Various fan tourney memes, such as the tendency for tourneys to sample JonTron's "WHAT?" sound effect and the overuse of Neil reps as a whole (which itself lead to the tourney Neil for a Day), were introduced here.
Mashup Week Megamix is the sequel to Mashup Week, with a doubled roster up to 32 characters. Many of them, as with KFAD, have been edited somewhat - a notable example being how Flat Eric teamed up with Gigi and Scoops, the latter of whom were originally a boss pairing in the original Mashup Week.
PRIZM is an unusual tournament in that each character is based on one of 16 individual colours, and due to the unique nature of this tournament's design, there are several fan variations of this (most notably PRIZM128, a tourney with no less than 128 individual contestants.)
Ultimus Tourney is another notable tournament, which is interesting in that it had Lo-Fi Girl as a contestant. Overall, it's quite safe, but still a high-quality tournament that, interestingly, introduced the concept of white noise being a villainous entity within tourneys.
Live for Another Day 2 is a tournament loosely based on Danganrompa, in which characters who are knocked out of the bracket are brutally killed. It's run with Monokuma as a host, too. It's somewhat unique in that it's one of the only popular tourneys to have its basis in a specific pre-established IP.
RAVE Week is a tourney that originated with the unique spin in that it only used rave.dj mashups in place of anything made by other people. The reasoning was mainly due to the number of low quality rave.dj mashups that were being sent as actual submissions to tourneys, which in some cases made certain mashup artists in the community incredibly mad in itself. It's not actually used rave.dj in some time, as they decided to drop that aspect of it, but it's still an interesting part of tourney history.
Bootleg King for Another Day 2 is interesting in that it's had a lot of negative reception from people on behalf of SiivaGunner (mostly due to the naming scheme, as it's not actually associated with them.) Even so, it's still high-quality.
Crown Crash: Double Dash!! is notable in that every character in the tourney is paired up with someone, hence "Double Dash!!" being in the name. There's some interesting pairings here!
[filthyfred] Key of Fate Tournament, a tournament I've actually been involved with (to a limited extent at least.) It's a hella sweet tourney loosely based on Super Smash Bros. Melee that you should check out!!