If you have:
1 factor
2 groups
and a between subject design
(assuming continuous DV & interval/ratio)...

If you have:
1 factor
2 groups
and a within-subjects design
(assuming continuous DV & interval/ratio)...

If you have:
1 factor
3 or more groups
and a between-subjects design
(assuming continuous DV & interval/ratio)...

If you have:
1 factor
3 or more groups
and a within-subjects design
(assuming continuous DV & interval/ratio)...

If you have:
MORE than 1 factor
ALL factors are between-subjects
(assuming continuous DV & interval/ratio)...

If you have:
MORE than 1 factor
ALL factors are within-subjects
(assuming continuous DV & interval/ratio)...

If you have:
MORE than one factor
SOME between-subjects and SOME within-subjects
(assuming continuous DV & interval/ratio)...