If your Xbox One is buckling under the strain of Overwatch or Doom, and installing one more game is finally going to tip it over the edge, it's probably time to buy an external drive and gain some much needed storage space.

This post contains the best prices available for each drive from all the major retailers. This should take all the pain out of tracking down the best place to buy, whether you're looking for a very specific drive, or just want the best price per GB.

I've deliberately excluded deals that are limited availability, or store-specific. Every product & price in the list is a nationwide deal, available to order online or pickup from a store.

The lists are in capacity/price order. In brackets you'll find the retailer and the code to paste into their website's search box to find the drive.

Portable drives (2.5" USB powered)
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1TB - £42.99 - Maxtor M3 (Amazon - B01AJWNYLA)
1TB - £43.17 - Samsung M3 (eBuyer - 396739)
1TB - £44.99 - Seagate Expansion (Argos - 142/7187)
1TB - £45.99 - WD Elements (Argos - 295/1047)
1TB - £48.00 - WD Passport (Amazon - B00Y0R9D6G)
1TB - £49.99 - Seagate Backup Plus (Amazon - B00FP50LH2)
1TB - £58.50 - LaCie Porsche Design (Amazon - B0058VIXBY)

2TB - £54.99 - Seagate Backup Plus (Amazon - B00G7LQA1E)
2TB - £59.99 - Seagate Expansion (Amazon - B00TKFEE5S)
2TB - £64.67 - Samsung M3 (eBuyer - 584735)
2TB - £64.99 - Toshiba Basics (Currys - 151644)
2TB - £64.99 - WD Elements (Amazon - B00D0L5BH8)
2TB - £67.90 - Maxtor M3 (Amazon - B01AJWNXAM)
2TB - £69.99 - WD Passport (Amazon - B00Y0R94PQ)
2TB - £88.84 - LaCie Porsche Design (Amazon - B00IZGR2V6)

3TB - £86.99 - Toshiba Basics (eBuyer - 708295)
3TB - £99.99 - WD Passport (Amazon - B00YRBNDAC)

4TB - £109.99 Seagate Expansion (Amazon - B017KE8OG0)
4TB - £114.50 Maxtor M3 (Amazon - B01AJWNWWQ)
4TB - £119.99 Seagate Backup Plus (Argos - 428/4815)

Desktop drives (3.5" main powered):
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2TB - £54.99 - Seagate Expansion (Amazon - B00UNA1O3Y)
2TB - £68.02 - Samsung D3 (Amazon - B00C9TEL46)
2TB - £68.99 - WD Elements (Amazon - B00H7TBBSW)

3TB - £69.99 - Seagate Expansion (Amazon - B00UNA1ICQ)
3TB - £78.53 - Samsung D3 (Amazon - B00C9TEOCA)
3TB - £79.99 - Seagate Backup Plus (Amazon - B00HSYI4I6)
3TB - £82.48 - WD Elements (eBuyer - 728118)
3TB - £94.64 - LaCie Porsche Design (Amazon - B007LHQVM6)

4TB - £94.99 - Seagate Backup Plus (Amazon - B00HSYI58U)
4TB - £95.99 - Seagate Expansion (Amazon - B00UNA1OBQ)
4TB - £99.99 - WD Elements (BT Shop - 9H00RR00)
4TB - £104.34 - Samsung D3 (Amazon - B00HZDRCRO)
4TB - £114.68 - LaCie Porsche Design (CCL - BAK4595)

5TB - £101.26 - Seagate Expansion (Amazon - B00UNA1O0W)
5TB - £109.99 - Toshiba Basics (BT Shop 9D68RR00)
5TB - £114.99 - Seagate Backup Plus (Amazon - B00IT2K1QE)
5TB - £119.29 - WD Elements (Amazon - B00NAQG0VY)
5TB - £142.00 - LaCie Porsche Design (Amazon - B00OD6KPAW)

6TB - £159.99 - Seagate Backup Plus (Amazon - B00SJBHPH8)
6TB - £159.99 - WD My Book (Tesco - 696-9259)

8TB - £189.99 - Seagate Backup Plus (Amazon - B00SJBHPYQ)
8TB - £193.88 - WD My Book (eBuyer - 742097)
8TB - £246.73 - LaCie Porsche Design (Amazon - B00S1LNNFY)

Found any of these even cheaper? Please drop it in the comments and I'll update the list!