@Touchfuzzy, you have no idea how much I'd wanna play Ryuutama! Lot of good ideas in that game, and a great feel to it.
To address
@Rubescen's OP: what kinds of games are you looking for, and how important is homebrewing to you? I've got a few recommendations across a sliding scale.
Old-School Renaissance / Old-School D&D Retroclones
These refer to games that borrow design choices from older editions of D&D, both AD&D (1st and 2nd edition) and even older (0e, Basic and Expert or "B/X"), etc. It's fascinating to see the roots of my favorite hobby. I think these are great for homebrew due to less moving parts, especially if you know D&D 3x through 5th edition well. Most are pick-and-choose and cross-compatible, too!
My personal recommendation is
Basic Fantasy RPG: it's free (with cheap paperbacks if you want physical copies), has a ton of support for supplements and modules, and has new-school nuances such as ascending AC instead of THAC0. These are mainly retroclones aimed at AD&D and B/X, but aren't the only recreations of older tabletop games. Beware, if played rules-as-written, older D&D is pretty deadly. However, I like to think of the rules as... suggestions; your house, your rules. >;3
Dungeon World
I. Flippin'. Love this game.
Dungeon World is based on Apocalypse World rules, and the basic playbooks for each class and GM stuff are also available. It's a narrative-based, fail-forward kind of game with decent crunch, resembling old-school D&D done in its own way. Aside from the basic rules, the game is played loose-and-fast and specific rules are written in plain English. No pedantic explanation of how the stuff works mechanically, but explained skillfully enough that it's easy to understand.
Core mechanic is rolling 2d6 + stat. A 7~9, where the bell curve of a 2d6 roll often lands, offers partial success with consequences. Experience Points are gained through failures at 6- (hence, failing forward) alongside personal and story-based accomplishments at the end of session, and not just loot or battles. Interestingly enough only the Cleric and Wizard have spells, but even quasi-casters like Bards and Druids have had their mystical powers rolled into their movesets without distinct magic.
The game has a core book, but even using the
printable playbooks off the website for free, it shouldn't be difficult to grasp for tabletop RPG veterans. The link in the first DW paragraph will take you to the game's SRD, which gives a more in-depth look to GMing and playing the game in a wiki-like format. It also explains stuff that the playbooks alone won't, such as item effects and tags. One last recommendation is this essay by a co-creator,
A 16 HP Dragon, which explains how the narrative and tags are way more important than statistics alone... and are fearsome when combined!
Savage Worlds and Everywhen
Looking to make your own custom-built game world? Didn't like GURPS, fearing redundancy in homebrew for Pathfinder, and don't wanna break the mechanics of D&D 3rd through 5th editions? This, my friend, is the wonder of Generic Systems such as
Savage Worlds Adventure Edition and
Everywhen! Both are pulp-inspired games with different feels, and I'll detail both.
Savage Worlds (or SWADE for its current edition) is described as Fast, Furious and Fun -- the mechanic involves rolling funny-shaped gaming dice based on skill level, trying to get a 4 or higher. It features an exploding dice mechanic, where rolling the highest number on a die means you roll again and add the total. There's plenty of material for various genres, using a skill-based system and feat-like abilities known as Edges. Powers describe generic magical effects to use with Arcane Backgrounds such as Magic, Miracles, Weird Science and more; each of these basic effects are encouraged to be customized. There is a "death spiral" for damage, but it also features reroll points ("bennies") to soak damage. The game has a good blend of crunch with customization, and there's quite a few homebrew settings and rulesets that use the Savage Worlds system floating about the 'net.
Everywhen is a generic system for an indie game known as
Barbarians of Lemuria, whose oldest version I'd peeked at can be found at 1kM1kT for free at that link. Characters have three sets of aptitudes with four stats each -- Stats, Combat Abilities, and Careers. One's careers act as skills and character backstory as one. The game only uses d6 dice, and not many of them -- roll 2d6 + stat + career / combat ability, and try to get 9 or higher. Weapons are simple enough, as are Boons and Flaws to customize characters; a bonus is 2d6 and keep higher, and a penalty 2d6 and keep lower. Arcane powers are potentially dangerous to use, but the effects are open-ended and fulfilling certain conditions can lower the MP cost. It's perhaps easier to piece together than Savage Worlds, if that is important.
EDIT: Aside from adding more info on Dungeon World, I hadn't realized you'd already tried Savage Worlds. Whoops!
I tinkered with a lot of systems including many that are no longer in print. Many of the group I mostly played with ended up sort of doing our own systems using ideas blended from features we liked of other systems. My own personal system I worked on eventually looked enough like GURPS that I ended up mostly just using that instead with minor modifications. For the most part I just like having fantasy mixed with modern day or sci-fi. You know like a dwarf riding a Harley wielding a magic wand sort of thing 
