Oh damn, this is a hard choice. However, let’s analyse it.
Vanessa’s look huge and, whilst they are certainly not small, they look much bigger than they are because of her super fit, pint sized body. Jenny is a bigger girl all round and those huge tits don’t just look huge. So, in conclusion, Jenny’s much bigger tits will crush Vanessa’s.
If this were just a question of whose are the most sexy, it would be much harder and my decision would probably be different.