OK I have no idea if this is the best of Yakima but it is what I found in 4 days there:

* Where to stay — we stayed in the Hojo’s, it was merely adequate. Locals tell me that the Red Lion and the new Marriott Courtyard are nicer
* Dining — Zesta Cucina was great! The find of the trip. Great atmosphere, and they handled our huge group (45+) well. We also dined at the Olive Garden — it was yet another Olive Garden — and at Tequila’s — standard chain Mexican but in converted railroad cars downtown so kind of fun. Both the Garden and Tequila’s also did a good job with our mob. In all cases, do the restaurant a favor — have one person pay and figure out how to break it up later.
* Lunch — El Grullense (near the Sundome) is a fine little taqueria. And Miner’s (also near the dome) is classic burger drive-in fare.
* Recreation — well of course if you are there for a high school state tournament or a state fair then you will spend a lot of time at the Sundome. Note that they have some fairly restrictive rules about fan behaviour for high school events so you might want to dig into it before you go – signs, bodypainting, too much standing, boomboxes — all prohibited. As is outside food of any sort.
* Other recreation — the riverwalk along the Naches and Yakima rivers is a pleasant walk. And you can get into the Cascades to the west in a half hour for hiking etc. The Naches Ranger Station on Route 12 is a great place to stop and get current condition info, maps, etc. Based on my experience – bring snowshoes if you are heading out in early march, because there aren’t many trails clear yet.