I don't know if my sense of smell is great but when I open Liberty or Sterling the character is fresh, herbal and "smooth" if that makes sense. Cascade is the original citrusy hop, right? I typically don't get citrus from the neutral hops I use like Mt. Hood, Sterling, Liberty, Northern Brewer, any German noble hop, Ultra, Santiam, Vanguard, etc. The Crystal I huffed last night had some slight Cascade action going. I also agree with Megary on checking the hops both visually and aroma-wise prior to use. What you smell from the bag *COULD* be what you smell in your glass of beer. I remember someone saying that bags of hops can be purged with a gas that might have that onion/garlic smell. I think I have experienced that smell too. I have had hops seem completely dead (no aroma) and dry, some that were no longer dark green, some with stinky gym-sock aroma and other unsavory things. I have gotten much more snobby about my hops. Hop Snob. Maybe I'll put that on a T-shirt.
Cheers Beerheads.