It's only relatively recently that the Darwin statue took centre stage and rightly so I think. Before then it was Richard Owen, founder of the museum and enemy of Darwin who sat where Darwin does now.
I think Wallace was offered the same burial in Westminster as Darwin, but declined. Wallace also sullied his reputation a little with some very strange ideas later in his life, and quite a bit of barking up the wrong scientific trees. Darwin kept his nose quite clean. But it's always been known as the 'Darwin-Wallace' theory of evolution, and was from the start. And we still use and call it 'the Wallace Line', the most famous biogeographical divide in biology.
And, at the end of the day, Darwin did come up with the theory of evolution 20 years before Wallace, but he sat on it until Wallace's letter forced his hand. I think if Wallace had published first and Darwin was now in his shadow we would rightly be talking of how Darwin was well and truly robbed.
Fundamentally, Darwin wrote the book that popularised the theory to the public - On The Origin of Species. So Darwin undoubtedly made the much bigger impact of thinking up and backing up the theory, and then popularising it. He started this 20 years earlier than Wallace, and had years of data from around the world as well as detailed experiments at home (on pigeons etc), which Wallace didn't have.
Darwin could have been as great as he was without Wallace, but I don't think Wallace would have had a Bill Bailey show on BBC2 if it wasn't for Darwin. He might have had the same idea, but he needed Darwin's detailed work to really nail it. Without it, others would have had to come instead of Darwin to provide the essential supporting data and experiments to get it fully accepted as quickly as it was.