I'd say it depends on just how much of a 'not team player' you are. If you want to be completely independent, developing small mobile apps, mods for games, Wordpress/Bootstrap themes, and projects like that where you can work for yourself and by yourself might be ok. If you want to code alone, but you can handle having a customer having the final say on any decision they care about, you can become an independent consultant/contractor. Next rung up on the teamwork ladder would be your typical open-source or small-business projects, where you work by yourself most of the time but your work needs to be reviewed and sometimes changed, and others will typically have the final say on decisions.

You say "best opportunities". If you're looking to earn a good living, that's hard to do solo. Very few people are good at all of the tasks that go into software development (and I'm including the non-development tasks, like sales and marketing of both the product and your development skills here). Also very few people manage to create a runaway viral hit on a small application (like Flappy Bird), where your solo work can earn enough so that you don't need to worry about making a good living on the other solo projects you choose to work on. For most developers, learning to work on teams with others is a crucial development skill.

One possible opportunity for a 'solist' could be so-called DevOps positions. They are often structured more as a group of loosely cooperating people working on independent tasks. You will get a lot more say in HOW you do things vs a traditional software development team. You will of course have to deal with doing Operations like work in addition to the development (how much vary a lot based on the company/job).

This is where I've ended up due after many years as a software developer at start-ups because you can land a more stable job that pays better while not being driven crazy by micro-management.

Trouble shooter, smaller projects where the output is very well defined (for instance: tuning and optimization), indie games.