1st off,
If you're like me, your injured leg will never be as big as the other one. You can easily get it as strong but after the muscles atrophy they just won't catch up size wise. I did my left ACL four years ago and currently my left leg is slightly stronger (I jump off my left leg, start with it forward etc...). However, the quad mass is ever so slightly smaller than that of the right--especially the vastus lateralis.
In my rehab I did tons of step ups and lunges. I was lucky enough to do it through my schools sports medicine (as I was currently playing college soccer at the time) and so I had a trainer do several specific workouts with me every day (for free).
We had one plyometric progression which I found particularly helpfu. Its length was a good 6 weeks and by the end my athleticism was restored and the strength balances eliminated.
In terms of strength exercises I think step ups are the way to go. I am always wary of bulgarians and lunges especially when the weight gets heavy--the twisting can be hard on the joints/ligaments whereas I feel the step up is safer and just as effective. I also think single leg, leg press is very good and safe. Finally, I recommend you start squatting earlier rather than later and squat in front of a mirror to make sure that you're doing so symmetrically and not twisting or leaning to favor one leg.
TL:DR: Do step ups, squat in front of mirror, your atrophied leg will never be as big as the other
