My vote goes to Like A Hurricane. I like Layla a lot and I think both songs get off to memorable and exhilarating starts with the opening guitar, but the difference for me is that Like A Hurricane never lets up, with the outstanding solos (probably my favourite guitar work on any Neil Young track) ensuring the song remains a thrilling listen throughout its length. By contrast, with Layla the piano section of the song, while by no means badly executed, seems too long to me - by the end of the track the exciting guitar rock of the first section feels long gone.
To summarise succinctly, I think Layla starts to drag towards the end, but Like A Hurricane never does, despite being over a minute longer.