I've been trying some todo list apps that have windows 8 version of its app. Effectual seems the most promising at the moment however I don't feel convenient with its UX.
I use the native Calendar app, which has a 'to-do' list and it two-way synchs to my Outlook Calendar, plus I can see it on Android tab, and outlook.com.
Only downside you cannot make a direct tile to task list but easily accessed from Calendar.
There are tasks apps on the store. With them you can have a tile. I use exchange, so I wont say what works with Outlook, but Im sure I saw few of them too. I have bought about all tasks apps that sync with exchange. Search the store.