Issue tracker / Project management

Hello everyone,

I've used many issue tracking and project management systems and I have yet to find something that truly works for everyone.

In case of TL;DR; skip to the end for the actual question. The rest in between is just background info about my team :)

/** background info 

In my current employment ( Maatwebsite ) we aren't really using any kind of bug or issues tracking system. For some projects we do use the default bitbucket issues and for Laravel/Excel we obviously use the Github issues ( Which is probably our favorite so far ).

The problem I've found so far is that 90% of the systems are way too complicated, look like they've been designed in 90's or are so simple it doesn't really offer what you need. Or are simply too expensive for our small team.

The biggest problem is that literally every member of our team has a completely different approach to working with issues. 
- Our manager really loves simple spreadsheets with one line per issue en limited info. Because it's very quick and everyone can understand it, even very non-technical clients.
- I myself like something with clear issues, with room for in depth information and states and even sprint management. Don't really work with very clear deadlines so extensive planningtools are useless for me. 
- I have a colleage that really likes Github issues and pretty much thinks it's the best thing in the world :)
- And one other that I'm still not sure about since just about every system seems to be lacking in one way or another.

I've liked redmine in the past. But it's in Ruby, so we can't really customize it as much as we would want. But there are many other systems that offer some nice features.

I would love an open source system but most just seems really outdated. Redmine again works very well, but everything about it feels old and customizing isn't really an option for us. And there are many alternatives.

There are many payed systems. DoneDone seems really nice, but since it's hard to convince anyone to work with a particular system a payed service is a very hard sell. 

 end **/

So, the question is. Is there an open source, or free service that has most if not all you need in Issue, bug and project management and still is easy to use, even for clients and looks like it's designed in this decade ?

/** another somewhat longish explanation, feel free to skip

If it really doesn't exist. We are considering building our own system ( obviously based on Laravel ) and we were wondering if the community would be interested in something new ? If not, we might still do it just for our own purposes, but if there is an interest we love any and all ideas on what features are essential, and would be optional. 
Our ideal system would have to be completely configurable ( via code, not wizards or anything, we would be aiming at developers ) and extensible with modules etc. 
Most likely it would be Open Source, perhaps with a payed hosted version to pay for the hours we spent on building it. But it might not be a very viable idea withing the current ecosystem of existing systems. 

end **/

So, that's basicly what I'm here to find out. Is there a system that really offers a very good experience. Or is there a market for a new system ( free or payed ) withing the community ? If neither is true. What do you use to overcome the shortcomings ?