England's best would presumably be Knight and Trescothick... July 2000 to March 2003: they racked up some 3500-4000 runs between them in that period... and the combination of brains (Knight) and brawn (Tresco) was extremely effective.
Gayle and Chanderpaul clearly deserve more recognition than they routinely get (not least as Gayle is also a superb ODI all-rounder). That said... I'd have thought they would have some way to go to match Ganguly and Tendulkar: they have something like 20,000 runs to their name when opening in ODIs... and I assume most of those were with them as an opening partnership!
Edit: just found the link to the page listing the combinations -
Code:
The best opening pairs in ODIs (at least 1500 runs)
Opening pair Matches Runs Average 100s/ 50s
Gayle-Chanderpaul 31 1639 58.53 5/ 9
Greenidge-Haynes 102 5150 52.55 15/ 24
Gilchrist-Hayden 80 3873 49.65 12/ 19
Ganguly-Tendulkar 117 5621 48.87 16/ 21
Gibbs-Kirsten 66 2838 46.52 9/ 12
Sehwag-Tendulkar 55 2441 44.38 9/ 10
Atapattu-Jayasuriya 78 3340 43.94 8/ 19
Gilchrist-Mark Waugh 93 3853 41.43 8/ 20
Gayle-Hinds 41 1687 41.14 4/ 5
Ganguly-Sehwag 40 1593 40.84 5/ 6
Ganguly-tendulkar have the most games, the most runs and the most 100s... and I suspect their strike rate was (at the time) right up with the best.