Coming from someone who has experience playing ice hockey. Also going to separate Sprint and Distance in Biking and Swimming
Olympic Medal:
1. Running (no brainer - every country competes. I would say sprinting and distance running are equally difficult in to medal. The cost to get yourself towards a competitive level: starting from $0)
2. Distance Biking (every European nation is a lot bigger in this sport than in Running so it is very competitive. HEAVY drug abuse in this sport says a lot about it)
3. Distance Swimming (technique is very important here and there are really only 3 events to pick from: 800, 1500 and 10k.)
4. XC Skiing (another very technical sport and very competitive in Northern Europe. Having said that, once you pick up the basics it seems to have a major similarity to long distance running. not too many medals in this event either)
5. Speed Skating (if you think you can get away with no technique in this sport, you are seriously kidding yourself. of the above sports, this is by far the hardest one to get an efficient movement)
6. Triathlon (yes, there is only one medal per gender. yes, very technical. However, LOTS of these guys are dropouts of biking or distance running. another sport that costs money to get started in)
7. Sprint Swimming (technical, but all you need is to specialize in a specific style and you have your pick of events to medal in. Also costs lots of money to have accurate distances to swim in)
8. Sprint Biking (Next to running, Biking is the least technical sport out there. The velvodome not only costs a lot of money, but also has way too many events.)