E17 Tallon : Very good tealc going rogue episode, beating up Mitchel, brutal fight with the bad guy.
E18 Family Ties : Not sure about the Valas father character, but you have to watch this episode for the ending, Tealc going to the theatre is just hilarious.
E19 Dominion : This is Ori crossed with Gauld and the thought is scarey, some loose ends are tied up here, Baal is always good for treacherous behaviour and he doesnt dispapoint here.
E20 Unending : The conversion to Star Trek is complete, time displacement anomalies and even food replicators. Its well done, interesting, but not classic SG1.
Hopefully the new stand alone movies contain the stuff that is obviously missing from these final episodes.