At 2, child starts to develop the milestone for 'imaginary play'. You shouldn't have all toys be geared for imaginary play, but there should be a mix of different kinds of toys to encourage the milestone developments.
We bought our daughter a kitchen set, plastic food, toy pots & pans and utensils. (I'm not saying you need to buy an expensive toy kitchen... Its pretty cheap to buy a set of plastic food and the toy pots & spoons and see if she responds. You can check out Target's toy section if Toys R Us is overwhelming). She also likes to cut the velco sets of plastic food, which helps hand & eye coordination. It might take her another 6 months before she can figure out how to put the velco food back together... that's a more advanced puzzle.
She also has a couple very basic, all plastic baby dolls (and she loves the one she can take in the bath!); doesn't care much for dressing her babies, but likes to pretend to feed, give bottles, cover with blankets and pat their backs. She also has a babydoll stroller (cheap, $5 at Toys R US) and loves to take her baby for a walk (or run!) around the house. Also enjoys the toy doctor kit or pretend vet kit (which comes with little stuffed animals)--especially if she can do a "check up" on mommy (or a friend/sibling). Medical kits are a good way to teach taking turns also, if one is the patient and the other the doctor.) My DD is a 2.5 yr old now; I think the next baby doll toy that we introduce will be the Baby Alive--not so much so she can 'feed' her baby, but I think the crying and laughing feature will be fun for her to react to.
I found a plastic tea set that she plays with in the bath tub... It makes washing her hair much easier when she's distracted! Also, one of the developmental milestones that daycare schools look for when deciding when a child is ready to move up is the ability to pour liquid into a cup... The best place to practice this is in the bath!
You might also consider a set of musical instruments. 2 is a good age to let them explore making "music". I think there's instrument set put out by Parents that comes with a drum, harmonica, cymbals, xylophone, etc.(?) Although, you might want to buy some earplugs for yourself!!
A few cars or toy trains (regardless of the child's sex) are good too. The cause and effect from rolling the cars are good and they can also make car or train sounds (which is good for the imaginary milestone). And if you can roll the car(s) back and forth between you and her, it teaches sharing and how to target/aim. Again, Parents puts out some big chunky wind-up plastic cars that are good for this. I think they come in a packet of 4 (at Target). The little Mattel cars aren't appropriate until age 3.
Playdough is a great for gross & fine motor skill development, learning how to manipulate fingers, hand muscles... Always a hit but you have to supervise. Non-supervised play with playdough is set at age 3. And even at 2, they're not really doing much beside squishing it and mixing the colors together. When my DD was an early 2 yr old, she liked to investigate the playdough tools, liked to poke at playdough with a tool, but actually seeing playdough squish out through the tool toys was scary for her (!); she didn't get over that until around 2.5 yrs. Always a hit if mama/dad makes ball for her to squish, but at 2 they don't has the mental understanding of how to shape balls themselves and can get frustrated (or lose interest in the toy) if left to do it themselves. And for hygiene reasons, you should try to replace the playdough fairly often.
Keep in mind that at this age, children don't have a long attention span. 10 or 15 minutes is probably the maximum that a 2 yr old can self entertain, and then its on to the next toy o, more commonly, finding out where mama is and what mama is doing... Which no doubt was some a evolutionary safe guard!...