which external hard drive is compatible with the latest MacBook Pro? is Toshiba a good match?

Compatible? Pretty much anything that will attach. You may need to reformat for Mac use.

Best? Look at reviews on sites like Amazon, but remember any customer review site will tend towards the negative since people who are happy often don't bother posting whereas those who have a gripe will want someplace to vent. My preference is to get a decent enclosure from someplace like OWC = macsales.com and then get a drive (by that I mean the metal box that goes inside) that gets good reviews. The last time I checked (about a year ago) Toshiba wasn't all that highly rated which probably explains why they are cheapest.

You may also want to state for what purpose you will be using this. Some drives are better suited to particular purposes.

All of them are compatible. The trend today is to get a SSD rather than a rotating drive. External drives often come pre-formatted NTFS for Windows so make sure you format it for your Mac before using it. Do not install any of the pre-installed utilities that typically come with a new drive.

Limnos wrote:

SSDs are quiet, light, cool and use less power but also cost a lot more per GB than rotational drives. Again, it depends upon what use you plan on making of the drive.

Rotational hard drives are of course acceptable (and cheap) for backups and bulk data, but make for lousy boot drives.

Almost any USB external drive should be compatible, but there are differences.

Some people prefer a setup that's made from a separate enclosure that includes a bare internal drive, such as what OWC does. However, many of these enclosures are set up

I personally recommend the Seagate Backup Plus series. Internally they use SATA III hard drives with a SATA to USB interface board. It's also optimized for power. Mine states a 168 mA power draw connected directly to a USB 3.0 port and 100 mA connected to a USB 2.0 hub. It also works on an unpowered hub when other drives in separate enclosures won't work at all on a hub.

https://www.seagate.com/consumer/backup/backup-plus/

I've got a Toshiba Canvio external drive myself and use it for a backup. However, I'm not sure I'd buy another one. They have an all-in-one setup where it's a single board on the hard drive that provides a direct connection to USB. If there's a failure in the interface then you can't recover by placing it in an external enclosure. Most WD MyPassport drives are made the same way. If there's that kind of failure then often the only thing that can be done to try and get an exact "donor board".

SSDs are quiet, light, cool and use less power but also cost a lot more per GB than rotational drives. Again, it depends upon what use you plan on making of the drive.