A desktop OS that doesn't suck.
Out of curiosity, what does "doesn't suck" mean to you?
- General purpose. Applications don't have to pay a fee to the OS maker be treated as applications.
- Simple, but aesthetically pleasing interface. Not trying to push weird paradigms (e.g. laptop/tablet hybrids UIs). Polished look.
- Applications are installed through regular files. Stores are acceptable, but only as frontends to this same file interface, not as replacements. It should always be possible to store the installer or bundle as a regular file.
- Consistent vision. Programs don't feel like they were developed by completely different groups of people with completely different purposes.
- No surprise updates. User has full control over the computer.
- Preferably open source.
Apple have been the closest to this OS nirvana (if you forget the open source part), but they decided to screw their users with spying and forced signing of applications instead.