Green Lantern: Rise of the Manhunters

I recommend going for this branch last, as the "Lantern's Light" ability will cost you a cool 100,000 points, and will not be purchasable until you reach level 10.

The way I ground the last 130,000 xp I needed was by playing the Mission 10 on Poozer UP UNTIL the final boss, once the cut scene for the start of the fight began I'd quit out and then start Mission 10 again. I found that I got about 6-7k points in about 4-5 minutes without too much difficulty. Mission 2 on Emerald Knight isn't bad either, but it only gives you around 4.5k in the same amount of time. If you feel up to it, you can replay mission 9 all the way though on EK again, as I racked up about 75k through the whole Mission. However, I found using Mission 10 allows you to get into a rhythm because you can skip all but one (short, 5 second) cut scene, there are no lulls combat, and the confined spaces allow you to use your constructs to good effect, as well as rack up combos. It also takes a considerably less amount of time than playing though full missions. Turn on your playlist/podcast of choice, and a little over an hour later later you'll have this and your Big Spender achievement.

I agree that this should be gotten last, as the other skills are far more important than Lantern's Light. And it costs so much! Wow, 100,000!

I used the level 10 grind method mentioned in Br0ken Ghost's solution a few times before realizing that there was an even easier way to get to 100K. You get less than 1/8th of the money/XP/whatever a level gives you normally when you go with "Select Mission", so this is much more effective. I was able to get about 75K in 10 minutes.

1. Complete the game - you'll want to do this because there's tons of points on the last level during a normal playthrough that'll help you considerably in buying everything,
2. Go to "Select Mission" and start a level on Poozer (assuming you weren't playing on this difficulty level in the first place)
3. Exit out to the main screen and go to Continue
4. You'll start out on the second part of level 9, on Poozer difficulty. There is no point difference between Poozer and Emerald Knight. Rack up those easy kills!

This should be a cakewalk for you if you've managed to max out everything else. I found that the Missile Pack works well here, especially on easy, since you get those Green Goblin-like hovercraft Manhunters that evade most attacks and the missiles have auto-lock.

Hope this helps!