When you think of a portable storage device, you think of something that can be plugged into a computer’s port to provide extra storage space. That’s true for the most part, but some can offer more, such as really fast speeds, a lot of storage, a convenient backup solution or a built-in mobile media server that works even when not plugged in. Here are some of our current favorites that collectively offer all of the above, and then some.

Seagate Wireless Plus

The good: Wirelessly adds 1TB of storage space to up to eight mobile devices. It can relay Wi-Fi Internet access and works well as a fast portable drive or as a robust mobile media server.

The bad: It could use a faster Wi-Fi standard and should include a car charger. Its Seagate Media app doesn’t natively support all popular digital video formats.

The cost: $199.99 to $247.98

The bottom line: If you have a digital library that’s larger than the capacity of your tablet and want to bring it all with you on the go, this is arguably the best choice on the market.

Buffalo MiniStation Thunderbolt

The good: The bus-powered and affordable drive offers fast performance via both Thunderbolt and USB and includes both cables

The bad: It has only one Thunderbolt port.

The cost: $173.99 to $229.99

The bottom line: Versatile, good-looking and fast enough for most applications, this makes an excellent buy for those looking for a portable Thunderbolt storage device.

Seagate Backup Plus

The good: It’s fast, flexible and good-looking. The included backup software works well and is easy to use.

The bad: It caps at just 1TB capacity, and its price could be lower.

The cost: $79 to $105

The bottom line: This device carries the flexibility of the GoFlex portable drive while adding performance and style to portable storage.

WD My Passport Portable

The good: Offers top capacity and fast performance in a compact, good-looking and sturdy package. It also comes with useful software, and it’s relatively affordable.

The bad: The included backup software doesn’t allow you to back up on a schedule.

The cost: $144.81 to $229.99

The bottom line: This would be an excellent portable drive for use with both desktop and laptop computers, at home or while on the road.