General list for things everyone has seen working/not working.
Let's see...
Reverse Polish - strange at first, but has a certain charm; this reverse math is beloved by evolution.
Rnd - It randomizes... Probably evolution's favorite command of all, lets bots be incredibly unpredictable
Ties - They're mouths, hands, and locomotion; little bit unwieldly but otherwise great.
Viruses - bit primitive, but mixes dna with amazing results
Epigenetic Locations - lets bots transmit basic information to their kids
Truncated Storage - not a common feature but I've found keeping locations stored to within 0-999 speeds up evolution a huge amount.
Reverse Resource creation - allows bots to create/uncreate resources(Positive value, create; Negative value eat). Lets bots consume resources they find, allowing for more niches in a sim. Also saves on memory locations.
Okay, that's all I can think of right now. Feel free to add.