In this topic (https://www.lemmingsforums.net/index.php?msg=108075), Guigui asked about an exit for the default style. It's the only main object not accounted for, and it seems worth adding one.
The questions, then, are - do we all agree that the default style should have an exit, and if so, which exit should we add? I'd suggest one of three options, in order of preference:
1) Crystal exit - it's the most generic-looking of all the OG-style exits, arguably the most recognisable, and tends to fit with most level designs.
2) Design our own - if we do this, I'd suggest using the Crystal exit as a base, and recolour it with as neutral a colour scheme as possible.
3) Pillar exit - since the other default objects (i.e. Entrance and Water) are from the Pillar style, it makes some sense to add the Exit from Pillar also. Counter-point would be that the colour of this exit is perhaps a bit too specifically identifying as Pillar, making it less suitable than Crystal.
I vote for option 2. Recolor the crystal Exit.