Personally, I don't think the Wii is a very good gaming interface (My son agrees with me -- he's studying Computer Science and Video Game Development, and is quite the gaming aficionado). It's not nearly as responsive as other gaming systems and injuries have been associated with the atypical positions you sometimes have to contort your arm into to complete an action. If you're going to get anything (and I can fully understand why you don't want to!) I would go for a PS3. It's a far more established system and has a much wider breadth of games available, especially educational type games for small children. It's also a Blue-Ray player, which is becoming the dominant technology, and will add dimension to the quality of even your standard CDs. You can also hook it into Netflix directly to download videos on demand to your TV (although this service has been unavailable for almost 2 weeks now because of a major break-in to the Sony servers). In addition, you can use it to play music and surf the internet.
Although I used to be a pretty avid gamer, I just don't have the time anymore. I played mostly when working out on a recumbent exercise bicycle, but now use an elliptical, so my hands aren't free to use the controller. We use the system almost exclusively for watching DVDs (including my favorite workout DVDs) and instant play movies from Netflix (as well as some great downloadable aerobics programs), and love it for this feature alone. You can usually find really good bundles on these systems (especially at Costco) starting around Thanksgiving time, and the PS3 actually costs a lot less than most good Blue-Ray players.
BTW, with your high speed internet connection, you can also download Netflix movies direct to your husband's computer. If you have a TV made within the last 10 years, you should be able to connect the computer to the TV as a second monitor via USB or RS232 cable, and hook in sound through the headphone port. (Works great for internet TV sites like hulu, too!)
The downside of these systems is that it's not just the "razor" that costs, it's the razor blades that really get you! Games can cost anywhere from $30 - $60 or more new, and $10 - $50 used. They can be addictive and real time wasters. There are some great inexpensive games available, but it's easier to get cheap games for play on the computer (especially through gaming engines like Steam). One of my favorite games for the PS3, though, is "Flow", which is totally zen and great for zoning out and really relaxing to. One feature that is really kind of cool, though, is that the system can be used to play multi-player games interactively over the internet. I would often find my son playing games with other players from all over the world, and talking to them through the PS3 (at no additional cost) using a Bluetooth earpiece.
I started getting educational computer games for my son when he was in first grade. Since they were already around, my daughter started playing them at about age 3 or 4. There used to be great software available that taught reading, math, science, reasoning, and history in really fun and engaging ways, but I don't know what's available now. My kids learned a tremendous amount from these games and I think they really helped them forge ahead in school during the elementary school years. I would play them with my kids to add insight and to help (but only if they really needed it). Some of their favorites included Treasure Mountain, Operation Neptune (math), Reader Rabbit (reading), Where in Time is Carmen Sandiego (history), Logical Trip of the Zoombinis (logic and reasoning), and The Incredible Machine (creativity and problem solving) and The Incredible Mind of Dr. Brain (science, creativity and problem solving). I have to say, I was totally blown away when my daughter was studying AP World History in 10th grade, and was able to use some of the information she had learned from the Carmen Sandiego game she had played at age 8 on the fly to respond to one of the test questions! It was on a period of Japanese history that they hadn't studied in class, and she ended up getting a 5 (top score) on the test.
I finally broke down and let my son buy a used Nintendo system (yeah, it was that long ago!) from some friends when he was 11, and then he earned the money and traded in the Nintendo to buy a PlayStation about a year later. I strongly regulated game play to no more than a 1/2 hour/day (including for myself), and with only software that was age appropriate until he was 15, at which time I would allow up to an hour if all homework and chores where done. At this point I also allowed him to get T (teen) rated games, since my daughter was also old enough that I didn't have to worry about it if she played the games, too. I've never been a big fan of the violence in some of these games, but I have to say that many of them are incredibly good brain teasers. If you get the right games, I think they can really be terrific for developing heightened reasoning and problem-solving skills. Some of the group game play is highly interactive and can be great for parties.