I've been to a few matches in Thailand and Cambodia in the past, but there is no local team (in the first or second tier( that I can regularly follow in my area at the moment, so I've been restricted to casually attending amateur/youth matches for fun only. Which is a pity, as the locals are extremely passionate about football and the atmosphere is quite nice, in general.
I'm particularly interested in Thai and Vietnamese football, so that's the two main leagues I try to follow, but certainly keep an eye on Cambodian League too, as well as the general news on the latest developments in the region.