I would be done with the NRL, I don't watch games that don't involve Manly as it is.
I would still watch the NFL, wouldn't pick another team, just follow certain players closely.
Would definitely still watch. Would casually follow the Bills until an exapansion team came in or if a team relocated then I would go for that team. Especially if it moved to Canada!
As for NRL, no way would I still watch it. I pretty much can't stand Rugby League these days but my heart will always be with the Broncos so I still have interest in it through them.
Hopefully the Browns do go under one day. Then I could follow a real team.