They have a crapload of other characters. The creator's site is Sunny World and there seem to be some other characters that look worth having there too. I've always found her axe spin to be fairly cheap, but she's cute and you can usually avoid it. Speaking of Kabuki Klash characters, I've had Tsunade, a little girl with an axe, for quite a long time. I also enjoy Mattasaur's Kabuki Klash characters. Orochi Herman's Setsuna, Kagami, Raiya, and Shadow Dio are my favorites. Riot of the Blood Rehabilitation Center is another great source of characters. I've kept ALL of his characters in my MUGEN. His Ryu is special in that he has Evil and Master modes if you select certain palletes. Personally I find these far more fun to play as. All of them have their own style that's quite different from the more faithful MUGEN conversions. Phantom of the Server has created many great Capcom characters. Splode's Randy from Guardian Heroes is somewhere there too. ShinRyoga's drawn Super Mario and Super Luigi are there. His Venom is probably the best out there and his Aska is good too. She floats everywhere and has a possessed purple afterimage and creepy laugh. Dark Chun-Li is more interesting then I thought she would be. He's my new favorite with high comboability (air combos :D) and nice supers. Tetsu is at heart a Ryu clone from some fairly unknown game. My favorite characters that can be found at Random Select's Hosted Creations-Characters section are Big Eli King's Tetsu, Dark Chun-Li. His crazy comboable Evil Ken, Evil Ryu, and Dragon Claw can all be found at the Mugen Institute. I'll start with the three legendary characters created by Reu (who recently passed on :(). It's of the few DBZ characters worth keeping. You have to see this one's Spirit Bomb attack.
The password for the download is toskomics if you didn't figure it out. Goku: toskomics' hires Goku is what I used to replace the old Goku someone recommended at one point. Note that I had to use winrar to unzip his characters that are in parts because winzip wouldn't for some reason. Muteki makes practically all the other characters. I had a harder time finding a hires version of regular Sol, but finally found the download links for Amachi's on his news page. Guilty Gear: Akutagawa made an Order version of Sol Badguy and a Ky.
He has great SMB3 stages and a nice looking hires screenpack too. The Sky Battle stage in my first screenshot is his. Ziltama makes amazing stages with all kinds of stuff going on in the background.
I was only really interested in the Night of Walpurgis stage to replace the lowres one I had. First off, Kung Fu Man's posted some here. Most new stuff can be found by looking at the Mugen Guild releases forum. I'll try posting as many of those here as I can find again. I've found many links to the original authors sites. Updating and replacing characters where need be. I've been refining my character roaster the past couple of days. I've attached my resized screenpack shown in the above screens. You can go through and resize your screenpack, but it's pretty tedious. Unfortunately your fonts and character select screen will now appear small.
People who already have WinMugen can simply replace their winmugen.exe with the one from the Plus download. You can get it at Random Select under Download Mugen. It allows for hires characters and stages as well as the old lowres ones. Recently a hack of MUGEN called MUGEN Plus came out.