My DH is on a TON of vitamins and supplements, but we found out he has extremely low sperm count and so we're trying everything we can to improve it. Anything is cheaper than IVF or adoption, which might be our only choice with counts as low as his. He is on Fertilaid, too but once he's done w/ the 3-month supply I'm not planning to re-order it. It's basically just a multi-vitamin with a proprietary blend mixed in. It has L-carnitine in it, but not as much as what has been proven to help sperm count, so I have DH on extra of that.
DH takes:
L-carnitine (2000 mg/day)
Acetyl L-carnitine (1000 mg/day)
Vitamin C (1000 mg 2x a day)
Vitamin B12 (1000 mcg/day)
Vitamin E (400 IU/day)
Fish oil (1000 mg/day)
Men's multivitamin with Lycopene
Fertilaid
Vitamin B6 (100mg/day)
L-lysine (500 mg/day)
So yeah, a lot

He's also having a varicocele repaired. His urologist thinks it is causing his count to drop since we were able to conceive without too much trouble before.
I've heard that Mega Men Prostate and Virility Formula from GNC is a good multivitamin (I just checked, it's on sale for $14.99 a bottle online). You want something with plenty of zinc, selenium,and folic acid. Also it's good to take extra Vitamin C for increased motility. Once DH is done with the Fertilaid I'm replacing it with Mega Men.
ETA: Lil Sunshine, you might want to check out the TTC with MFI board for more info. It can be kind of a slow board, but it's a good place to get support from ladies who are dealing with the same issues.