Out of the ones on the poll it has to be Ireland, they've been playing for a hundred years and have a good chance of qualifying for the next World Cup as the next ICC trophy is in Ireland.
Argentina and the USA aren't as good as they once were, the USA need to get some American born players playing the game.
Canada are one to watch in the future, they should get ODI status by the end of the decade.
Denmark are on their way, they take part in the C+G trophy in England and matches even get shown on TV there.
Kenya are obviously the next test team.
Namibia were lucky to qualify for the World Cup, playing in South Africa's Standard Bank league should help.
The Netherlands are also one to watch in the near future, they have some good young players and had a good performance in the World Cup. Since the BBC stopped showing cricket (they can get in Holland) interest in the game has declined. They're considered good enough to be playing an A team in the C+G Trophy.
Scotland are another team to watch in the near future. They were unlucky not to qualify for the last World Cup, participation in the English National League should help.
UAE have a great stadium (Sharjah) but people only seem to be interested in watching teams from other countries there.
The next World Cup will probably have 16 teams in it. Kenya will almost certainly have test status then, so there will be 11 automatic entrants. I think the qualifiers will be: The Netherlands, Canada, Scotland, Ireland and Namibia.
After Kenya, look for the Netherlands to be the next test playing nation. That is a while off though.