If your child's feet touching the rear of the seat, this is normal. You can get a convertible car seat but try to keep her rear-facing as long as possible, up to the maximum weight or height allowance of the seat (rearfacing). My son is 3 1/2 right now, 32 lbs and 39", still comfortably rearfacing in a Britax Boulevard, but our back seat is tiny (we have a Subaru Forester) and the front passanger seat is almost unusable.
The best car seat is that which fits your child, your budget, your car, and can be installed correctly everytime. More that 80% of the time, they're not. Have your car seat (with your child) inspected - Safekids does free clinics nationwide or can recommend a police/ fire department that can check the seat installed by you. You can find a carseat check up event in your area here:
http://www.safekids.org/in-your-area/car-seat-check-up-ev...
The new edition of the book "Baby Bargains" has a good overview of the car seats on the market with pros and cons, plus ratings. You can also check consumer reviews on amazon for different seats, usually they are very helpful.
You can also check out http://www.carseatdata.org, an online resource for parents seeking guidance toward the best car seat for their family, lifestyle, vehicle, and budget. It matches your car model year with other parent's opinions about car seats that fit (or not).
In terms of seats in general (for any car), the most recommended from a safety and ease-of installation point of view for an older baby is the Britax Roundabout, sold at amazon for $179 or at Buy Buy Baby in NYC for the same price (with a very flexible return policy) if you use a bed Bath & Beyond blue coupon (they own the chain). The seat works up till 2 1/2 or so, depending on the size of your child.
Some parents go for the larger Marathon (65 lb frontfacing/ 35 lbs rearfacing, $220 right now on amazon) but there are now many other options out there that have high weight limits rearfacing. Look at the maximum height allowance and also the height of the shoulder straps, as children oftentimes outgrow the seat by height, not weight.
When buying though, check the return policy. Brick-and-mortar stores like Buy Buy Baby and Target are the best options. Babies R Us and Walmart have a good assortment, but prices tend to be just as high and the quality sometimes inferior (thinner fabrics, less padding, etc.) Amazon has great prices but their new return policy has increased return S&H significantly and the box must be unopened (it used to be a fixed price per type of item but now the price varies according to your order).
www.elitecarseats.com is another option, they have an interesting lifetime return policy for new and unused seats; return S&H is free if you get their Return Shipping Insurance. The site offers many options and objective reviews on different car seats, as well as customer service support (note: I don't work for them but from my research this site was one of the best).
Keep all tags and stickers on the seat, box and receipt so you can return the seat if it's not a good fit for your car or your child. It needs to be almost rock-solid with side-to-side movement of less than one inch once istalled, with about two fingers clearance from the back of the front seat to give some room in case of a collision. Some give is normal, side to side or front to back - Safekids can advise you on this and help make the install more secure with the addition of pool noodles or a rolled-up towel.