Q:

Push/Pull/Squat vs Brosplit

I am 26 years old, been working out for about three years now.   I have not been sticking to my program for about 6 months, only lifting 1-2 times a week (working college student). 
My schedule has opened up, and I should be able to stick to a program for at least a few months, what kind of program will produce the most gains? 
I have tried a split before (Mon:Chest, Tue:Legs, ...) but had almost no result, probably because I found it so boring.   I made decent progress with SL 5x5, but am open to trying a split again. 
So should I take my new strength back to curls and leg extensions, or would it make more sense to continue a full-body routine? 
My goals are to get bigger and stronger, just to be clear. 

A:

If your goal is at least in part to get stronger, you're best off exhausting your beginner gains with a beginner program.  You already have experience with StrongLifts, so it shouldn't be hard to get back into it.  Just start back at ~50% of your 5rm for each lift, or take the Starting Strength approach and use a week to test your current lifts and start 30-40 lbs below whenever the bar starts to lose speed during each lift. 
If you manage to stick to StrongLifts and plateau a few times, I'd recommend deloading and then switching to Starting Strength, since it will involve lower volume which will allow for better recovery.  It's up to you ultimately though if you want to also replace rows with power cleans. 
Once you stall out of Starting Strength, you will have a very solid foundation and will know where your maxes for each lift are.  This will make it easier to accurately work with percents of your max for particular rep ranges if you want to start training for hypertrophy or continue training for strength.