I used to always have acrylic nails and recently I had gel ones..
Acrylic nails and completely sculptured - so they make up the nail with a mixture of powder and a liquid solution, this then hardens and it filed down and buffed up.
You will need them 'filled in' every 3-4 weeks..
Gel nails they stick a nail tip onto your natural nail and then build up layers of 'gel' which hardens over the tip and on your nail...
I would go for acrylic every time... they look far better than gel, they are more durable than gel and they last longer than gel nails - i found that I needed the gel ones 'filled in' after just 2 weeks and started looking tatty after a week.