You might take this with a grain of salt since it's coming from a skinny dude who works out for reasons other than weight loss.

There's nothing wrong with a half hour of cardio at a time. There is such a thing as too much cardio, especially if your diet isn't planned around supporting a lot of activity. Even if you're not into weight lifting or body building there's plenty of helpful information here: http://scoobysworkshop.com/does-cardio-burn-muscle/
Muscle burns more calories than fat, so more muscle = you burn more calories even when you're just sitting.

Something to combat the boredom factor could be high intensity interval training. Sorry to throw another link in here but I'm rubbish at explaining and don't want to accidentally give oversimplified or bad information:  http://en.wikipedia.org/wiki/High-intensity_interval_training

For cardio, I do different stuff, which helps minimize boredom. Yard work. Long walks. Dancing for 10 to 30 minutes to fast techno on youtube. There's tons of music on youtube and some of the videos are convenient workout lengths, so stopping to pick another video is avoidable.

Eating spicy food is supposed to help metabolism a bit too, if you like hot peppers it might be worth it to work them into more meals.

Editing this in, a digital food scale combined with reading nutrition labels makes a huge difference. What I used to pour for "a bowl of cereal", not knowing how much it really was, probably double or more what I pour now that I can measure and choose how much I need.

I also like Jack's suggestion. I took Karate (quite a few years ago). I think Jack does Tae kwon do, but there are tons of different types. It's goal directed in a way and has a history and even spirituality (you can get into these aspects as much or as little as you want, btw), which I found interesting. If you don't go for those aspects at all, you can do something like cardio kickboxing. It uses martial arts moves without the belts and tournaments and stuff, but I found those aspects fun. It gives you a heck of a workout. With a real martial art, you have a dojo or school where you meet other people, who are usually pretty nice.

For diet, well unless you are really overweight, I think the "clean diet" (no not cleanse-- yuck!!!) ideas are good: shop around the perimeter of the store (the inside is more of the crap), also frozen produce, and you can buy  whole grain bread and pasta and condiments (like mustard and vinegar). Say away from highly processed foods and lots of added sugar and salt (as well as things you can't pronounce). Staying away from a lot of fats and sugars is good. Learn how (if you don't know) to prepare about 10 different *meals*.

Here's a blog post: http://www.blogilates.com/blog/2014/01/27/my-ultimate-eat-clean-grocery-list/

--Jay

I hate cardio, I hate running, I can't swim and it makes me super dysphoric...but I love to ride my bike and I like to do stairs. I think the best thing would be to do a cardio where you're also building muscle. I've done insanity and the reason I liked it was because you drip and sweat but you're also super sore because you're ripping your muscles up.
For the diet thing, whoever said diet will make you lose weight and exercising sets you up for failure is wrong. I have a diet which consists of what jay said. Everyone's body is different. Experiment with what you find interesting, keep at it for a few months if you don't like it after that change it. I've seen guys do super clean eating, I've seen flexible dieting, I've seen "dirty" eating if it fits your macros, and people have all had the same results. I do agree with weight lifting, muscle weighs more than fat and it also helps burn fat. Build muscle if anything, just try to get 30 min of cardio 3x a week.

I've been studying nutrition for years and am currently in a graduate program studying to be a registered dietitian (the highest certification for nutrition). I helped a friend lose 65 lbs last year. PM me if you'd like some help.

As for exercise, most of these are great ideas. The main thing is to find something you enjoy doing most days of the week (3-6 days) and will stick to.

@not your average guy-- you can *lose weight* by eating a diet full of additives. Losing weight is a matter of eating fewer calories than you lose. However this kind of diet isn't really very healthy.
The OP asked re ideas on an improved diet, as I recall.

--Jay

OP you can try sprinting

http://www.bodybuilding.com/fun/par46.htm

you should totally try plymetric exercises. they're high impact though so if you have knee problems it's probably not  a smart idea.

but it's like jump training. you jump around alot, really good for your legs and it's also great cardio. i know p90x has a great disk for plyometrics but look around online for things you could do.

also swimming. if you have access to a pool not only can you get cardio but it could really help you build muscle.