AUSSIE MOIST: I love Aussie, it leaves my hair soft and manageable, I can comb my hair easily when wet and any tangles are easy to work through. Even when my hair has new growth, it helps a lot to make the tangling that can occur during this time easier to handle; I've found a better conditioner for detangling my hair with new growth though but Aussie is still a staple. It's heavy and thick and my hair feels like butter when I'm rinsing it out. It CAN have the tendency to be oily though if your hair is naturally oily or you use a lot of product.
VO5: I like VO5 products and almost anything made by Alberto Culver but I haven't tried the Moisture Milks line which is the one I'm assuming you're referring to. I do know it's runny though and people use it for cowashes and like it a lot. I notice more people use VO5 than Suave for this purpose, not sure if it's because it's better, cheaper, or more available though.
SUAVE: A lot of people tend to use Suave conditioners for co-washes, they're runny. I used Suave once in the past and it made my hair come out straight AT THE TIME when air-drying made my hair poofy. Although, my hair wasn't easy to comb through and my hair was left broken...
erplexed I was a pre-teen at the time so this information concerning Suave isn't recent. I also wasn't well-acquainted with my hair's needs and specific rules in terms of care.
Overall I suggest the Aussie Moist, it gives nice slip and it actually makes my hair feel like the title suggests for at least 5 days. If co-washing is your thing and you want something quicker to apply to the hair try Suave and VO5 but if you don't mind a product with more viscosity I believe that Aussie Moist will be more satisfying than the other two. Everyone's hair is different though but I'm just saying that I would suggest Aussie over the other two.