I have used Tdex and SideSwap for peg-ins. Tdex does a "real" peg-in every time, forcing you to wait 102 blocks whereas SS will handle small amounts instantly, which I assume they use their own balance for. I generally use SS myself although I prefer to hold funds in GreenQT.
Sideswap peg-in fees
0.1%
Tdex peg-in fees
0%