I got a d3100 for Christmas and it came with an 18-55mm lens and as we all know you can only use a kit lens for so long.
I'm planning on buying a new lens for more landscape / architecture / wild life pictures
What do you guys suggest? I was thinking a 70-200 but I'm not too sure

Also, do you think it's worth getting a flash? I plan on getting the 50mm lens for portraits. 90% of the time they'll be done outside around sunset so I think I could benefit from one.