Moon Race and Heart Throb. Lightning link. 

You must be betting wrong. I have won 2 grand jackpots on the Lightnings, one on Vegas Money (the Gold case feature and casino chips) and one on Magic Pearl (the Dolphins and Pearls), plus so many Major JP's also. Not much luck on the space machine, but I don't like playing it anyway. Try $1.25 or $2.50 bets on 1c denomination on either of the first 2 machines, but avoid 2c denom if changing, only 1c, 5c or 10c denom, but no more than $2.50 bets. I almost forgot, it depends on the day and time you play them also as they are programmed to pay out the bonuses at certain times. Surely you have heard a number of machines all paying bonuses or getting free spins at the same time? Not coincidence, nor random like people will tell you. Take note of times they go off and write them down, then check them each month. You will see a pattern emerge, of the times you should play them and when not to.