What is the closest TTC subway station to Brampton?

I'm at Sandalwood and Chinguacousy in Brampton and I'm looking for a way to get to a TTC subway station via Brampton Transit only. It can be any one. I'm looking for which is closest/easiest/fastest to get to from my area and how to get there. (How to get there isn't a big part because I have an iPhone that will tell me, I just need a location) I'm open to possibly going through Mississauga but I want to only use 1 Brampton transit transfer.

It's not possible to reach the subway by taking only Brampton Transit. Here are a few suggestions using a combination of Brampton Transit and YRT/Viva or MiWay.

1. Take Züm route 501/501A east from downtown Brampton. Anywhere between Hwy 7/Martin Grove and York University you can transfer to Viva Orange (free) which will take you to Downsview station.

2. Take Züm route 502 south to Square One, where you can transfer for free to a MiWay bus (3, 20, 26 or 109) which goes to Islington station.

There are no free transfers between the TTC and other transit systems.