What animal species could be removed from Earth with minimum impact on the food chain or the environment

Everything feeds on everything else - large birds eat smaller birds and mice. But mice have their place, eating grain and dispersing seeds with their spoor. So every animal either is food to another larger animal or, if it eats grains and seeds, helps these to be distributed and planted elsewhere.
So what one animal has absolutely no use at all on earth, doesn't form part of this?
My own theory is that if you removed humans from the earth then it wouldn't really make much of a difference - the food chain would continue and nature would get into a balance.
Am I right? Or what one species could be removed with minimum impact on nature and the food chain?

Roach Bugs could go away and we'd never miss them

none to remove any one, will have some effect on some thing else.
which will damaged , some thing else.
its like a bike wheel, keep removing, a spoke and it collapse.

If you removed humans you would have a massive impact. Lots of species would increase, domesticated animals would probably decrease cause they can't look after themselves, and pest species, like rats and mice would probably decrease, because humans wouldn't be producing waste to feed them and so would eventually decrease to what the environment alone could sustain. There is actually a show where they did a simulation of what the world would look like if the humans were all beamed up or something. Basically it has a massive effect on the biosphere, and it would have a largely positive effect.

Every animals is linked in the food chain. Removing any one would result in a change, though it would depend on the animals how big that effect would be. Anything that eats or is eaten, or uses natural resources in any way will have an effect on the environment if it is removed.

If you remove something from a food web there will always be an impact.
The smallest impacts I could thin of are:
-Some types of plants
-Megamouth sharks
-several insects
-some bacteria and viruses
You also say food chain; that's but when I try to answer this question I like to think it as food WEB. Because if you take out a producer (plant) for example, in a food chain everything would die but in a food web/eco system It will be affected but not every thing will die.

Take a look at the diference:
Food chain: http://www.google.com.au/imgres?imgurl=h…
Food Web:
http://www.google.com.au/imgres?imgurl=h…

And for the person who answered that everything would be better without humans (I agree):
http://www.google.com.au/imgres?imgurl=h…