I go through about half a kilo of veg every day, eaten with every meal regardless of pro/fat or pro/carb, with a huge portion before bed so I can sleep on a full stomach.
Any kind of veg is good, but a very cheap and tasty way is to buy big bags of the frozen stuff, I get peas, broccoli, carrots, sweetcorn, peppers, mushrooms and cauliflower. I fry some chopped onion in a little olive oil until brown, add the veg and two cans of chopped tomatoes, turn the heat down and let this simmer until it's reduced to my desired thickness. You can also add spices, oregano, etc this way.
I'm not a huge fan of the taste of greens but this way mostly you taste the spices/tomato and still manage to pound down the fibre.
When it's in season, a fresh rocket, coriander and lettuce salad is ace.
For fruit it's whatever's in season, eaten with or between meals. I also add a bag of frozen mixed berries to a few lbs of oatmeal, stir in some nonfat/lowfat yogurt and refrigerate, it's the best way I've found to eat oats, I used to eat 'em raw with water but that got old..
