@Aaron Taniguchi - "to each his own" is what initially comes to mind. It really depends on YOUR individual circumstances. You didn't specify details (such as 'is the tenant living next door')....
So Ill take a stab. IF they lived next door and this is your first property, I guess "in person" collections might work. If its across town I would personally suggest some form of electronic collection. THen again, how big are you planning on growing (again unspecified).
Cozy is a decent offering - it works well for a size of one up to mid-sized operations... then again, I switched providers at 10 units as I had outgrown cozy. I believe Zillow is now in the game as well. Both are "free" with some caveats (it takes 3-5 banking days to get paid), however you've got "proof" the rent was in fact paid. I had previously used ErentPayment, however that WAS a paid service - and after their implosion last fall I would NOT recommend them.
THere are also options like zelle and other P2P apps that you can transfer monies... something to consider for a single unit, but then again its not going to scale with your business.
Id say it really comes down to asking WHAT do you PLAN to aspire to, and how much of an investment do you need/want to make in systems at this point? Id personally steer you towards cozy - Im guessing that it will be a good fit for just getting started