Using gmail to make "to do list"

It's really too pity that google calendar doesn't provide to-do-list, or called task list, though this has been argued by the users for many times from long time ago, including me. But google forsook us :( (What I gained is I learned a new word "forsake" from those posts.)

Someone said we can create a new calendar, and list the to-do-list by setting the events as daily happening. If we want to update the list, just click it, edit it, and then save with the option "only affect on from the day after". But there are at least 2 shortages: 1. This calendar hold too much space of the page of the whole calendar, and looks ugly; 2. If you update the events and click "for all the events", it will update the past events, which is not what I want. And what's more, the use of this kind of new calendar is not the official usage, feeling weird...

Now I find a new method by gmail sending email to myself and using the filter:
1. create a new tag, for example called "To-do-list";
2. create a new filter, "from" myself, "has word" TBD (just example); click "next", chose "mark as read", and "label" To-do-list";
3. now we can use it:
3.1 write an email with title: "TBD ... ", with/without content in the body of the email; then this email will be labeled as "To-do-list", and marked as read (as we don't want to read it immediately again);
3.2 when we want to check what should I do, click the label "To-do-list"; and if I finished one of them, just remove its label. And how to check what I have done? Search "TBD" and from myself.

Is is perfect?