I know Portland Cutlery (NW Knives Portland) quite well. It's a fairly small store, and doesn't always have that much. From time to time they'll carry a whole line, but then as production, season or stock falls, they can get sparse. What they do have is a variety, and knowledgeable employees. Another great thing about them, I assume it's intentional, is that they carry knives and lines that other stores don't have.
So for example Sur la Table a few blocks away carries Shun and Global, etc. (also Willams Sonoma down the street) whereas Portland Cutlery carries Messermeister and Kyocera ceramics.
The old guy that works there, with really awful teeth, is quite knowledgeable. I don't know if he's the owner, but he sure seems like it, he's there all the time after hours.
Bottom line: if the Portland Cutlery store is so nice, the Eugene one must be either the same level of coolness, or even better, because someone mentioned that's the main store. Try it. For your edification, the Portland Cultery store is diagonally NE from Nordstroms, right downtown. Rich's Cigar Store is west two blocks and north one on 9th and Alder, and has the best selection of pipes and cigars, as well as a mountain of magazines and Newsapers. If you want to try your luck, ask for Sam or I think the guy's name is Rich, he's got red hair and chops, young guy around 30. Both know their stuff. Prepare to spend some time if Sam helps you, but he's almost telepathic with his recommendations. Steve, the odd tall guy with grey hair and chops is the pipe guy, and knows more about pipes and tobacco than anybody else in the world, except for a handful of people.
There's a couple great watch stores within a couple blocks, plenty of audio-hifi shops, Powells Bookstore (think Amazon.com with store shelves) and one to two blocks away you have some of the best dining in Portland. On Morrison between 7th and 10th there's at least a dozen good Indian, Persian, Italian and such restaurants, and on the corner of 10th and Alder is Jakes Grill, a super cool restaurant over a hundred years old. In the bar area you can smoke cigars and watch games, and the restaurant (in the same room) has fine cuisine. A few blocks down the street, on 11th if I remember right, is Jakes Crawfish, one of the best seafood joints anywhere. Jake's Grill has a cool thing where every day between (call them, they might have tweaked the hours somewhat) 3-5 and 10-close is happy hour in the bar area. Drinks are the same for the most part, but you can get a very good 1/2 lb cheeseburger, fries and a tiny green salad for $2. They have other happy hour food too, for very cheap. Some of the dishes are just appetizers, but the cheeseburger and chicken sandwich are real full courses. Check it out. Jake's Crawfish sells oysters on the half, and has a variety that you may have never seen before, fresh as fresh can be. There's a couple other really great oyster shops in town, but I don't know how committed you are to finding them; look them up on Zagats.
While I'm on the topic of food, I would be a fool not to tell you about one of Portland's real jewels, Voodoo donuts. They're open such odd hours, it makes them perfect for a capper to a whole day in Portland. Their hours are usually 8PM to 10AM. Don't be afraid if their store seems closed, just knock on the little side door and hope that someone opens up. Often on non-weekend nights, they keep the lobby closed to keep out the bums. Call ahead just to make sure and stuff, 503.241.4704 is what google maps turned up. They're such an oddball place that you really just have to go; they sell donuts like you've never imagined, with peanut butter and butterfinger chunks, grape sparkles and grape jelly, even a really funny one that I can't mention the name of that is very popular with bachelorette parties; you'll know it when you see it. They also sell totally normal run of the mill donuts, and their crullers are to die for. Do yourself a favor and order a "Voodoo Dozen" and ask them to pick half normal donuts and half crazy specialties. Or, if you've got the whole family, ask if they have a "bucket of donuts." It's literally as many donuts as they can fill into a bucket, mishmashed of all the types that didn't sell the day before. Voodoo's donuts are so well made that even two and three day old donuts are fresher than what you find at most donut shops. I HIGHLY recommend them. One proviso; ONLY CASH. If they have them, the buckets are $5, and the voodoo dozen is usually $8. If you pick and chose the most interesting donuts for yourself, even if it's a dozen, you may end up spending quite a fair chunk of change. Try the voodoo spike; it's like a churro donut with cinammon sparkles.
So in other words, you can make a hell of a day of it with your wife. Be prepared to spend some dough, if you are so inclined. Realistically you can have a good time without spending money, it's just so much better when you do. I'm sure I've missed some of the best features of Downtown Portnad, but as with most things in life, exploration can be its own reward.
Furthermore, check out Sportsman's Warehouse both in Eugene and Clackamas. I don't know the Eugene store, but the Clack store has a very good selection of knives, fishing and hunting gears, etc., and some very knowledgeable employees. Don't be deceived when you walk in and only see one long counter with knives. Pay a little attention, and you'll see that all the major brands are displayed, at very reasonable prices. Not counting kitchen knives, Sportsmans probably has more knives than Portland Cutlery. FWIW, the drive from downtown to Sportsmans would take you about 20 minutes without significant traffic, and then you're only a couple blocks west of I-205, which will lead you right back to I-5 and Salem. They close somewhat earlier than you might think, so call ahead.