Virtual_Singularity :
Have you compared rest of the specs other than storage space? WD and Seagate are bigger names than Toshiba in storage currently, it's possible the Toshiba drive isn't as fast, may be refurbished, etc. In regards to WD and SG, their latest external drives come with backup software that require your agreement to their EULA for use (privacy policy says your info can be used in any way the companies deem appropriate), thus basically making what's supposed to be your external drive theirs, by regularly sending any info you put on those drives back to WD and SG. Unsure if Toshiba does the same thing. Just figured that's worth mentioning.
Aside from that: No reason to assume Toshiba's drives are inferior just because the one(s) you're looking at cost less. If you're looking for an external drive for backup, there are other drives worth looking into as well. Fantom drives, & others offer quality external drives that are reasonably priced. And if using for backup, you'd be the one that chooses what method or software to use, rather than vice versa.
The models are:
Toshiba Canvio Basics 3TB USB3.0 2.5 HDTB330EK3CA
Western Digital My Passport USB3.0 2TB 2.5 WDBYFT0020BBK-WESN
Seagate Backup Plus Slim USB3.0 - 2TB 2.5 STDR2000201
In terms of specs, Toshiba seems to be a smaller and also a lighter drive (100 grams lighter) compared to the €105 Western and €100 Seagate. Everything else is identical and the speed is reliable:
http://www.techradar.com/reviews/pc-mac/pc-components/storage/disk-drives-hdd-ssd/toshiba-3tb-canvio-external-hard-drive-1296244/review
I will use the drive mostly for storing photos, films, music, etc. Therefore, it will be accessed on a regular basis but it won't be moving around much, perhaps once or twice a year to a trip.
I have been looking at HGST Touro drives as well. They seem to be high-quality drives (at least based on the reviews I have read online) and they are in the same price-range as WD/Seagate.
Any recommendations for high-quality brands to look at except for the aforementioned Fantom?