Jira is king but Asana is the revolutionary upstart. It has some lightweight nifty features I'd like to see in Jira
* Follow feature.
The reality of many modern projects is that contributors are dispersed geographically and across organisations - a dev team in Bangalore , a designer in Cape town, an investor in Kerry. The magic of this follow feature is in it's simplicity in adding contributors to a single task.
Asana makes this easy. Add any email address to a task or project and that person -internal or external- can monitor and contribute to that individual task or project with a 5 second sign-up. They can immediately add comments to a task just by replying to an email. They only see what you want them to see.
I've used this recently to keep a lot of people updated together. I created a task called Project Update and had a dozen followers with various interests. They simply replied to that task via email which was added to comments. They didn't have to log in to anything and Asana kept it all quite neat.
* Quick entry
Press enter for new task, type, press enter - done.
We need a bulk entry system in Jira - and no, CSV uploading is not what I'm talking about.