The number one eatery in Lausanne for price, quality and abundance is the food court type Manora located right at St. François. For Chinese excellence and the lowest prices I suggest Chez Xu. Near the Cathedral is an inexpensive little restaurant with a garden in the back that is a hangout for intellectuals and medical students.
Down from St. François is a very German style restaurant bar called Bavaria with lots of charm and is affordable. Historical and almost an institution is the Café Romand at the place Saint-François where as a local, you will run constantly run into people you know.
In a part of the older section of town is a very tiny fairy-tale like pub called Pinte Besson, another Lausanne institution. Still up in the center of town, the Java café is also a good value for something light.
Down on the lake at Ouchy is the lively White Horse Pub where you can always find someone speaking English and eat affordably. Just around the corner with a lakeview is the MGM Café with light fare which turns into a nightclub much later in the evening.
Buffalo Grill is actually a French chain restaurant in the Crissier area serving tex-mex and "American" food which is actually quite tasty and inexpensive.
Place de la Riponne 10
18, place du Général-Guisan
In the Beau-Rivage Palace, Ouchy
rue de la Mercerie 5
Jazz and Whiskey Lovers Look Out!... read more
avenue de Cour 74
Tennis and Thai - Oddly Worth it... read more
route d'Oron 1
Simple Environment With Good Food... read more
escaliers du Grand-Pont 3
place Chauderon 5
For Those Who Have a Big Appetite!... read more