Free Slots
I now much prefer the free spin slots, but mainly this is because there is no predetermined upper limit on the maximum possible win as there is on many of the pick bonus slots.
One of my favorites is Munchkins, as with 20 spins it is less likely to give nothing. Cabin Fever is also good in this respect, with the added bonus of wilds doubling the win.
Worst of all is going hundreds of spins with no bonus and then getting almost nothing when it finally comes along.
I am not that keen on Mermaids Millions as the 10 free spins nearly always gives nothing, and is virtually impossible to get in the first place. Tally Ho is a litle better as there are some decent reel wins in normal play, even though the bonus round seems to be all or nothing. (Just imagine 5 scatters or 5 wilds in a 4x free spin round! - I'll take 5 foxes too!)
The 3 reel slots are fine, but rather boring. Good for completing a WR on a bonus, but I believe the house edge is higher than on the video slots. The arrangement of comps and WR at BelleRock between Video slots and 3 reel "standard" slots only supports this view.