Running

C25K is your best bet, as it takes you from total beginner to running for 35 minutes. If you have a smart phone, you can buy anapp for it that will tell you when to start and stop intervals. Otherwise, you can find plans online and time yourself.

If you are looking for a little extra spice, there's an app called "Zombies Run," which has a full story line and has recieved a lot of praise for entertainment and effectiveness.

Definitely C25k. Done it twice and its a great way to get in shape enough to run a 5k. Its not "easy" but after you get past week 4 or so, its smooth sailing. I actually think that it gets much easier once you get past the interval training and start running without walking in-between.