Currently it is only possible to select as default assignee either "Unassigned", or "Project Lead" (more in the Enterprise version).

It would be nice to be able to set "Current User", i.e. the creator of an issue, as the default assignee.

We have a lot of small teams using JIRA, with a large volumne of issues, and they would have benefit of this option - as they currently have to select themselves as assignee, each time they create an issue.

(and the list of possible assignees is rather long as the issue may have to be routed to any of the other 300 employees in our company)