$20 to $30 is my usual deposit size
I second goatwack's suggestion of 'Georgie Porgie', it can be a brutal and unforgiving slot at times but at 0.15p and if its playing even slightly nice you will get great game time because the wilds are x5 and x25 in bonus round. Theres potential for some decent size wins even at 0.15p.
'Hearts and Tarts (Queen of hearts)' would be my second favourite rhyming reel slot (30 lines stacked reels in free spin) followed by 'Jack and Jill'. Avoid 'Nat King Cole' thats easily the worst rhyming reel slot.
Other suggestions :
rivieria riches (MG) - bonus round triggers alot (in my experience) and its 0.15p a spin at minimum
mystique grove - 243 way at 0.25p, no free spin but bonus round usually pays x10 to x 20 and easy to trigger
jewel box/lady of fortune - can do 0.15p betting and its kind of high variance and bonus round does not trigger that much but inbetween the dead spins if you land any 3OAK-5OAK with x2-x5 wilds in reel 3 it pays quite nice
lucky witch (MG) - 0.15p minimum bet kind of high variance free spin round is crap but the bonus round is good. base game has stacked wilds that only combine with the top 3 symbols so its a pretty streaky game
barber shop (thunderkick) - can do 0.10p bets - kind of jack hammer clone - key is to try get a bonus round where you get enough respins for x5 because it will pay out really nice. can last a long time playing this game on minimum bets
Fat Lady Sings - 0.25p bets, kind of medium variance you usually get something in return every spin even if its really small. free spin is one of the best for an MG game it combines everything (stacked reels, multipliers, bonus game)
Pretty much every netent game at 0.20p can do as well any can catch hot and give you great playtime but I prefer MG because I seem to hit 'big wins' and freespins more regularly on MG. Good luck!