Torque app on your phone (free) with a Bluetooth reader (<$10).

Edit: Don't leave this connected all the time. I've seen it cause weird errors if it's always connected. Just use it to read codes, then throw it in the glove box.

If you just need a scanner to get and clear the codes, grab the cheapest one you can find. No point in spending the extra money on one that connects to the Internet and/or diagnoses your codes if you are mildly competent at using a search engine yourself.

Auto parts stores might do it for free.

I have a cheap Bluetooth dongle with an app and a plug-in handheld device. Both scanners read all my cars except one each, but each device doesn't read a different car, so I'm covered.

I prefer the Bluetooth dongle. It's more modern, but the setup/pairing sucked for me. The handheld device either works right away, or it doesn't.

Recently watched a video where they compared expensive vs. cheap Chinese auto tools, and the OBD scanner was one where the $7 cheap Chinese one outperformed the $200 whatever bullshit "fancy" one. For whatever it's worth. Very, very much just one anecdote based on one video.

As mentioned elsewhere, if the only thing you want to do is read codes, a $10 BT dongle and a phone app is going to be just fine.

But if you want to do more involved diagnosis, you'll need something better. HF has Icon branded diag tools, like this one (which is the cheapest of the three). I haven't used it myself, but Eric O from SMA has some Icon model that I've seen him use and be happy with.

Just get the cheapest wired OBDII you can find. Don’t have to worry about an app and pairing.

Ancel makes a cheap one.

I have one by foxwell that is a bit more robust. I like its live data capabilities. If you’re gonna be going any deeper than just codes might want to consider something like that.

My go-to is an OBDLink MX+ dongle, and their OBDLink app (which is just a white label version of OBD Fusion with free plugins if you own the dongle).

Torque is the oldie-but-goodie.

I would get one that can do live data and graphing/history. I was diagnosing an intermittent stalling issue and it took me a while to determine the ECU was seeing zero RPMs when the engine stalled. It was a Kia, turned out to be the crankshaft position sensor.

bluedriver and the ios app are the best — 99$ and even provides “most common cause & fix” suggestions for codes that pop up — you can get it on amazon

If all you need is OBD II, then you have a lot of great cheap options here already. It's definitely worth having a cheapo one at least.

Just in case you aren't aware though, OBD II is required by the US government for emissions reasons, and lots of car manufacturers will have their own proprietary codes on top of those that may not be read by any old generic OBD II scanner. To get those codes you'd need that car manufacturer's proprietary scanner, and that's going to be a lot more expensive.