The custom ones with new gear and monsters.

I personally enjoy OSRS servers, sometimes customs. depending on the quality

PvP Server!

Osrs balanced eco/pvp servers

I like 317s because they remind me of the time when I started playing rs.

But overall, I prefer the RS3 rsps, reason why is for practicing on bosses before I attempt them in RS3. Just to minimize the risk of dying and to know what I'll be up against before risking.

317 for nostalgia for sure

current rev (at least 180 or higher)

Close to current rev but also customs are decent.

317 for the win all the fking way 

Emulous servers, with "original" style gameplay. 317 - ~500 rev.

377-464.

The sweet spot; when you didn't need massively OP equipment.

pk server!!

i like pvp gambling rsps

718 ftw

I'm also in the 718 boat!