How to make chicken not so bland?

There's a couple of things that would be helpful for you. First of all, never buy the thin chicken breasts. They cook very quickly and turn dry almost at the same time they are finished cooking. If you want boneless, go with regular chicken breasts (If not, chicken thighs are great!). With thick breasts, give em a pounding with a meat tenderizer/rolling pin/your fists until it's more or less the same thickness across the cut of meat so it will cook evenly. Personally, I think the key to making the best chicken is a cast iron skillet, a meat thermometer, and a decent spice blend. If you don't already have a cast iron, get one and thank me later because they are THE BEST. Heat up some olive oil in the skillet on medium heat and toss your chicken plus your desired spice blend on there. Flip frequently (~a minute or so) until it starts to get a nice golden brown and the thermometer reads ~155-160deg. Pull the pan off the heat it will continue to cook the meat for a few more minutes. Chicken is officially done at 165 deg, don't let it get hotter than that or it'll dry out and be gross. Reheat in toaster oven or on stovetop if possible instead of microwave.

Really, the world is your oyster when it comes to spices. I prefer to use spices over marinades to cut down on calories and make a batch of chicken more versatile for several dishes. I highly recommend flavored salts. I have a smoked sea salt and a habanero salt that give some killer flavor without needing much.

Here are some examples of spice blends:
Au Naturale: Salt, pepper, garlic powder
Classic Herbed: Rosemary, thyme, sage, (or use Herbes de Provence instead of these three), salt, pepper
Spicy Mexican: Paprika, cumin, chile pepper, onion powder, garlic powder, salt, pepper

Also, try this one which is slightly different:
Lemon and rosemary: Saute fresh chopped rosemary in olive oil until crispy. Strain the rosemary out. Cook chicken in rosemary oil, season with more rosemary, S&P, garlic. Halfway through cooking, add lemon juice. Garnish with more lemon juice before serving. You could do this with balsamic vinegar or mustard if you aren't feeling the lemon.

Good luck, hope this is helpful!