I played around with Trello and it's all about cards. My problem is that I want lists, not cards. Haven't used Asana yet. Basecamp seems to be the best fit for my needs (I want to see what has been checked off and create repeatitive processes).
It was deceptively simple to get started but really powerful once I was able to dig in a bit more. Super responsive drag-drop UI and apparently it uses Meteor as the back-end so change updates are instantaneous.
It uses both lists (that can be nested multiple layers deep) and cards. You can drag tasks from lists to cards, or from cards to lists with links between the two being maintained. We were using the cards to track ToDo/Working/Done and lists to plan releases and track suggestions.
The project seems really young but they're doing all the 'right things'. One of the project contributors set it up to trigger notification updates in Slack when the boards changed and apparently it even has GitHub integration now.
I'm in no way affiliated with HansoftX. I just think it's a pretty amazing tool.