Execution speed question

[Suresh Pillai]

That's a good comparison for the general question I posed.  Thanks.  
Although I do believe lists are less than ideal here and a different data 
structure should be used.

To be more specific to my case:
As mentioned in my original post, I also have the specific condition that 
one does not know which nodes to turn ON until after all the 
probabilities are calculated (lets say we take the top m for example).  
In this case, the second and third will perform worse as the second one 
will require a remove from the list after the fact and the third will 
require another loop through the nodes to build the new list.