They are all AER rates. The PTSB and KBC ones are subject to DIRT at 33% and PRSI at 4% (for self-employed currently, and everyone from 2014).
The 3 and 5 year state savings (Savings Bonds and Savings Certs respectively) are completely free of tax.
The one with the "net" amount is the 4 year National Solidarity Bond. It's more complicated because part of the interest is taxed. It pays an 8% lump sum at the end of the 4 year term which is tax free, and 1% each year which is subject to the 37% tax (33% DIRT + 4% PRSI).
So the calculation is as follows:
8% over four years = 1.94% AER.
Additional 1% per year less 37% tax = 0.63%
1.94% + 0.63% = 2.57% Net.