Many people - commentators and fans alike - will put the 1993 race at Donington as Senna's greatest race. The opening lap has been called "the lap of the Gods" by some. The funny thing is that Senna didn't see it that way. His car had traction control (just as the Williams did but not many others on the grid) which made life easier for him as he is quoted as saying.
Senna held his first ever win - in the wet, from pole, in Estoril in 1985 as his best (or, at least, he held in much higher esteem than the Donington win).
Highlights videos of each race are here:
Estoril
Donington
Estoril was wetter and the cars lacked driver aids. We can see why Senna considered it above the Donington performance.
It's also notable how full the grid looks with c.26 cars. I think it would be nice to go back to bigger grids, but that's a different topic altogether.
Also, notice a certain Rubens Barichello leading a certain Michael Schumacher early in the race in Donington. The Jordan had TC, the Benetton not, ironically, at this stage of the season.