EOS technically has zero transaction fees so long as you use the wallets that stake some EOS for you which you have paid when creating the wallet like the Tokenpocket or Exodus. Users of EOS wallets can access dapps and use these dapps with free transactions to them so if you are looking for the lowest, it's going to be EOS.
TRX is considerable because they are fast and transaction fees are low too. If I have to choose between the two EOS and TRX though I'd personally choose TRX because of the number of dapps that I like.