My favorite one - the solution that was suggested at the conference: introduce the second type of blocks that contain transactions only and issued 60 times more often, every 10 seconds or so. Those blocks are not for determining winner of reward, so they won't cause orphan problems. This solution will give us 60 times more space for transactions and reduce confirmation time 60-fold! I think it is the perfect solution, even better than lightning, since it's not hub-based.
This is the solution that came out of people associated with p2ppool: fold p2ppool protocol into core protocol as a proof-of-propagation through proof-of-work. It is at over a year old, I've discussed it on this board in October 2014:
Re: Increasing the block size is a good idea; 50%/year is probably too aggressive
https://bitcointalk.org/index.php?topic=815712.msg9245823#msg9245823and I don't recall if I haven't seen it elsewhere before.
But then as usual within the Bitcoin milieu: it is more interesting to try to follow who was opposing that type of proposal and with what kind of argumentation; e.g.
a) is vulnerable to sybil attacks
b) smothers the incentive to include any transactions in blocks: why should I (as a miner) include a tx if the fee would go to someone else?
Also it seems both are too disruptive to be implemented in bitcoin.
Anything this much different would take an altcoin to be tried.