Manila has been influenced by Spanish, Chinese, Japanese and American Culture. You can see it clearly in our food. We can never be accused of bland taste :)
Some suggestions for casual dining places:
Teriyaki Grill - They serve japanese food with filipino taste. I always always order their chizu maki (chicken roll with cheese $3), tofu steak (with wonderful sauce $3) and california maki ($2).
Chef D'Angelo - Pasta, Pizza and Chicken. Best seller is their White Pizza (seafood with lots of cheese $3) pasta paella (a different take on pasta $3) and spicy chicken (kind of like buffalo wings 3 pcs for $4). Their German chocolate cheesecake is also my favorite (and I don't even like cheesecake).
Figaro Coffee Shop - Competitor of Starbucks. I love their little "Oscar" (sansrival $1.5), Bread pudding with warm vanilla sauce ($1) and their Chorizo pasta (pasta with sausage $3). However, their hot chocolate was very disappointing since I caught a server using the regular SwissMiss.
Dencio's - If you want Filipino food, this is the place to be. Try the sizzling bangus belly (milkfish $3), nilaga (boiled beef with vegtables $4) and gambas (shrimp with sauce $3). The bottomless ice tea is the cheapest I had ($1).
UCC Vienna Coffee - It's a Vienna themed coffee restaurant home based in Japan but located in the Philippines! This cafe is pretty expensive. But their salads are pretty good ($4) with wonderful wonderful Asian dressing and my absolute favorite Samba Cake ($3). A brownie like cake with molten chocolate inside so that when you cut into it, the liquid chocolate comes puring out. Can't beat that.
Ref Crab - Value for money, this is the place. Their buffet cost around $10 and it's all you can eat crab. Not only steamed but with different sauces. Other seafood as well. My favorite is the thermidor prawns.
All of the restaurants above are usually situated inside the malls. So, it's pretty safe.