We went a couple of weekends ago... don't know where you're staying or what sort of things you're after, but here's some random thoughts:
It's worth going up the towers, but it's not mind-blowing. You only go half-way up, you only see that area of the city... If you do want to go, you need to queue in the basement under the towers in the morning to get free tickets - if you're not there by 8am, don't bother trying. We got there about 7:50 and were within about 50 places from the back of the queue. We were told originally that it was 1 ticket per person, but it's not true, so if you're not going alone 1 person can get up to 5 tickets. We did get a pair for a German couple who had apparently got there about 10 minutes late, but it was pretty cheeky of them to ask, and I wouldn't rely on it.
We ate a couple of times in Nandos - the gf likes their chicken - once in the basement food area of the Pavilion mall, and once at a nice local-style place called Pelita Nasi Kandar - 24-hour affordable Indianish food a block or so from the towers. I liked it a lot, both the food and the style of the place, but my gf isn't so keen on curry so not really her scene.
We did go to the Batu Caves, although I was too lazy to walk up the 272 steps to the caves and hung around at the bottom. Also, a few veggie curry places here.
Went to the aquarium in the KLCC mall... there's a street of middle eastern restaurants (turkish, iranian, lebanese, etc.) we walked past which I could find the name of if you need it...
If you're wandering around the town, grab a decent map, and take a hat, sunscreen, water and an umbrella - in the two days we were there, it varied between very hot and sunny, and heavy rain...
You can easily grab taxis around town, but make sure they use the meter unless you're going to/from the airport. There are regular cabs and 'executive' ones which cost significantly more and aren't worth it unless you're desperate for some luxury... Walking is quite easy within neighbourhoods, but got taxis, the monorail and the underground a few times. 7-11 everywhere as usual is good for cold drinks...
Did find that people were generally friendly and helpful, with pretty good English.
We're not going to hurry back, although there are more things to do. I'm interested to see if they make any outright grabs for Bangkok's tourist market - it's a pretty comparable place, and obviously Bangkok is on the ropes right now.