The 25 year mark is getting to be quite rare in this day and age, so that's really reason enough to celebrate. The official theme for this year is silver. That's more like it, right? Cause there's sooo much you can do with this theme. Apart from the obvious choice of jewelry, the other gifts that you can present include silverware, engraved silver key chains or a ƈ and 5' days vacation at an exotic location (second honeymoon, why not).
75! Take a bow, please. Not many are lucky to celebrate their 75th wedding anniversary, so you should be terribly proud of yourselves for being with each other for all those years. The official theme for this year is diamond. I'd urge upon the jewelry again. A ring, a pendant, earrings or simple diamond studs. Awesome, awesome.