Legs Workout

Here is the legs workout I've been doing. I've been able to do it a twice a week for the last few weeks. Not sure what I'm going to do when I start Air Alert, perhaps I can do Air Alert and legs on the same days, talk about tired legs!

I start out with a core workout (same whether I'm doing lower or upper body)
Incline crunches w/ med ball: 2 sets of 10 (10lbs)
Incline obliques w/ med ball: 1 set of 20 (6 lbs) - I haven't gotten up to 20 yet.
Hanging Leg Raises: 3 sets of 10
Lower Back Extensions: 3 sets of 10 (5lbs) - Today will be the first time I've added weight to these.

I'm not thrilled with the abs workout. The gym I go to has an oblique machine but I hate it. The incline obliques I do work my abs a lot too so I am limited to 3 sets of the two exercises total. Any suggestions for an exercise that isolates the obliques more?

On to the legs:
Leg Press: 3 sets of 8 (360lbs) - I recently maxed out the leg press machine at the gym (500lbs) so I had to switch to a different machine. It feels completely different, still getting used to it, hopefully I'll be able to up my load quickly.
Lying Leg Curl: 3 sets of 8 (110)
Lunges: 3 sets of 8 per leg (80) - Done with barbell on shoulders. I tried holding dumbells but my arms get incredibly fatigued doing 3 sets of 8 on each leg. I like these better than the leg extensions as they're easier on my knees.
One Legged Squats: 3 sets of 8 per leg (100) - Like regular squats, but you put a bench a foot or two behind you, and put one foot on the bench allowing you to isolate one leg.
Hip Adductor: 2 sets of 15 (135) - Maintaining the groin, pull it once and you never want to again.
Hip Abductor: 2 sets of 15 (140)
Seated Calf Raises: 3 sets of 8 (135) - These almost cramped me up last time.
Standing Calf Raises: 2 sets of 20 (100) - I can't go over 100 lbs on this thing without hurting my back. So I do these for endurance which I need 'cause my calves are always the first to cramp.

I have two different basic approaches to leg exercises. For most exercises I do 3 sets of 8. You don't want to do too many reps if you're trying to build power and explosiveness. I do this for most of the big muscle groups. For support muscles I try to go for more endurance, so I'll do more reps (15-20). I do leg press instead of squats simply because I've never learned proper squat form and squats scare me. Maybe if I continue to enjoy the one legged squats I'll try some regular squats. I should probably be doing both leg press and squats. Someday.