The general perception is that the soviet union lagged behind the US in most respects, but surely there were some areas in which it was superior? Obviously they initially excelled at space travel, but I'm more curious about ways in which they had a sustained and systematic superiority.
One could arguably say at sports, mainly the Olympics. As it stands the Soviet medal count for both Winter and Summer is 1204, second overall to the US, who has 2681 (and with Great Britain at third with 806, the USSR isn't leaving that spot for a few more Olympics still).
But consider that the Soviet Union only first competed in 1952, at which point that US already had won 862 medals dating back to 1896 (816 Summer, 46 Winter). And that the Soviet Union ceased to compete after 1988, the US won a further 778 medals (617 Summer, 161 Winter). That's an extra 1640 medals (1433 Summer, 207 Winter) the US won that the Soviet Union wasn't even competing in. Take that away from the all-time total, and it becomes 1204 USSR, 1041 US.
We can further look at individual Olympics: When the USSR competed, they won the overall medal count 13 times in in 19 Olympics (6/10 Summer, 7/9 Winter) and never finished worse than second. The US finished first 4 times: 4/10 in the Summer, with the rest being second places and two third place finishes; Winter their best place overall was four thirds. I count the 1980 and 1984 Summer Olympics, boycotted by the US and USSR, respectively (and their allies), for the sake of consistency; each one finished first in the games they attended.
So looking at the numbers, the Soviets completely dominated at the Olympics when they were there. This doesn't even begin to touch on other sports; my biggest focus is ice hockey, where the Soviets were huge internationally, but as the US was not I won't write about that. I will note that this dominance in sports came out of a desire to prove that socialism could defeat capitalism in athletics, and the government put a lot of funding and effort into making this happen, with results that showed, even if it was more the result of a totalitarian government rather than socialist doctrine.
The USSR had a knack for designing and producing globally popular weapon designs (note that some cases the numbers are helped by units made by Soviet allies):
-The MiG 15 is the world's most-produced jet fighter and the most produced jet aircraft, period. If you discount WW II aircraft it would be the most produced combat aircraft of all time.
-The MiG 21 is the world's most-produced supersonic fighter (making it the world's most produced supersonic aircraft by default). It is also the second most produced jet, military or not.
-The AK-47 (with its improved versions) is the world's most-produced automatic weapon and the most produced firearm, period.
-The T-54 (including the T-55 and Chinese copies) is the most produced tank of all time.
-The Mil Mi-8 is the most produced helicopter of all time (inevitably many are in civilian use but the same could be said of the second-place Bell UH-1 and its derivatives).
The above are all Cold War examples. I should also mention that the Ilyushin Il-2 fighter and the T-34 tank were the most produced fighter and tank (respectively) of WW II, and the former is the most-produced combat aircraft of all time.
One that I'd think that might be outside of the expertise of many here (and I'm certainly no expert here either), was the use of phages rather than antibiotics for the treatment of infection.
Development of these separate therapies existed concurrently through the cold war, but has increased in importance as antibiotic-resistant bacteria have become more prevalent.
I'm surprised no one mentioned espionage, but in the field of intelligence gathering, the USSR out-spied the US. This ability allowed the Soviets to produce an atomic weapon in 1949, a far shorter time frame than U.S. intelligence sources predicted. It also gave them a edge during negotiations during and after WWII because recruited sources provided information about where U.S. policy was firm and where it could me manipulated.
In contrast, the majority of foreign agents the U.S. tried to infiltrate into the USSR were captured and killed or placed in Gulags. Stalin's network of spies within country kept a close eye on any foreigners because he distrusted any non-Soviets. WWII Soviet army veterans were also considered untrustworthy by Stalin because of contact with Western decadence and targeted for Gulags, as well.
Sources:
Chris Ward, Stalin’s Russia, 2nd ed, Reading History (London : New York: Arnold ; Oxford University Press, 1999).
Anne Applebaum, Gulag a History (New York: Anchor eBooks, 2010).
Zubok, V M, and Konstantin Pleshakov. Inside the Kremlin's Cold War: From Stalin to Khrushchev (Cambridge, Mass: Harvard University Press, 1996).
As you mentioned the Soviets are considered to have had a lead in the space race earlier on. Eventually they were surpassed by the US and were never able to catch up.
This is true for other areas as well, I wouldn't be able to point to a single field in which they were ahead continuously during the cold war. If they were ahead they seem to have always lost the advantage at some point, and if they were behind they never caught up.
It's hard to point at a single reason why this happened, it's more of a combination of many factors that led to this. For example:
Edit: my reply deals with scientific fields only, I seem to have misinterpreted the question as dealing with science only.
Well first obviously oil and in particular coal production, they at one point even had a 19% global share in :P
Agricultural production, in particular is something they were much better at, at least, looking at numbers in FAOSTAT where they seemed to be the number 1 producer in agriculture until China started surpassing them in the late '80s. Percentage wise according to GDP, the USSR made 20% of its GDP in agriculture in 1991 and the US around 1% in 1990.