Asked the same question last year before going to Pattaya.
Here are some responses.
Without a doubt the best fillet steak to be found in Pattaya is the beefeater in Soi Diana. Soi 11/12 on 2nd Road.
For Italian food I'd go to Cafe Volare on Soi Buakhaw corner Soi 15 directly across the road from Nature View hotel.
Hilton buffet Soi 9
Steak and Co Soi Lengkee off Soi Buchkow
Patrick's just a few metres away on the other side of Central Shopping Arcade beats Beefeater for Aussi/Kiwi steak.
As for Italian, my favorite is Little Italy, on Second Road opposite Royal Garden.
For Italian, Fire & Stone on Central Road, left side about 100 meters before beach road.
I have always enjoyed the Pattaya Beer Garden. It has a huge menu (Thai, Italian and much more) and I have tried many dishes and have no complaints, Food is fresh, prices are good and the service is fast and efficient.
Food in Kitchen (French owner) is good. 1 in second road between Soi 11 and 12. Another on beach road close WS
Brooklyn Pizza, Soi Diana, closed Tuesday. Closest to NY style I’ve ever had in Thailand.
Big Pizza just across from Soi 18 in Naklua is pretty special, the Hopf at the beach end of 13/1 has its own pizza oven and is great though LB's are not welcome in that establishment.
La Trattoria on Beach Road near Soi 6 is very good too.
Lone star Texas grill on Soi Lengkee very nice ribs and burgers
Hope this helped.