I noticed there're tags that are actually the singular and plural forms of the same term, e.g. string and strings, and I guess most of them should be merged. Here're some possible candidates (tag counts are as of 7/17):
Edit: grouped tags by count and sorted alphabetically.
> 1000:
- array (575) and arrays (878)
- database (3703) and databases (14)
- event (158) and events (871)
- exception (218) and exceptions (864)
- file (601) and files (612)
- generic (57) and generics (1032)
- image (589) and images (539)
- string (1187) and strings (277)
500 - 1000:
- browser (610) and browsers (43)
- class (532) and classes (151)
- compiler (639) and compilers (44)
- function (284) and functions (316)
- list (476) and lists (229)
- pointer (112) and pointers (400)
- session (557) and sessions (125)
- table (415) and tables (128)
- template (217) and templates (532)
- tool (44) and tools (919)
100 - 500:
- blog (37) and blogs (111)
- bug (45) and bugs (197)
- build (276) and builds (15)
- callback (27) and callbacks (107)
- certificate (145) and certificates (33)
- checkbox (152) and checkboxes (14)
- connectionstring (7), connectionstrings (17) and connection-string (95)
- constant (24) and constants (84)
- constructor (245) and constructors (25)
- cookie (80) and cookies (359)
- cursor (52) and cursors (52)
- dataset (191) and datasets (91)
- driver (84) and drivers (49)
- entity (85) and entities (23)
- example (30) and examples (87)
- field (68) and fields (50)
- filesystem (78) and filesystems (276)
- folder (54) and folders (72)
- game (85) and games (134)
- iframe (344) and iframes (10)
- integer (132) and integers (14)
- interface (307) and interfaces (171)
- key (53) and keys (48)
- language (207) and languages (48)
- method (109) and methods (169)
- model (231) and models (25)
- number (61) and numbers (76)
- object (211) and objects (176)
- password (106) and passwords (177)
- path (217) and paths (42)
- pattern (67) and patterns (137)
- pipe (27) and pipes (87)
- problem (97) and problems (25)
- process (337) and processes (150)
- project (78) and projects (108)
- property (115) and properties (300)
- script (256) and scripts (61)
- service (275) and services (126)
- set (45) and sets (69)
- stream (101) and streams (120)
- struct (156) and structs (15)
- style (171) and styles (77)
- tag (62) and tags (169)
- temporary-tables (233) and temporary-table (18)
- theme (34) and themes (108)
- timer (78) and timers (110)
- timestamp (117) and timestamps (8)
- timezone (161) and timezones (7)
- trigger (46) and triggers (213)
- type (99) and types (176)
- update (268) and updates (19)
- user (112) and users (90)
- variable (119) and variables (307)
- vector (186) and vectors (18)
- video (434) and videos (19)
- view (132) and views (106)
- widget (54) and widgets (86)
< 100:
- alert (20) and alerts (24)
- app (34) and apps (11)
- border (51) and borders (10)
- character (44) and characters (37)
- container (32) and containers (56)
- disk (35) and disks (15)
- expression (67) and expressions (21)
- group (41) and groups (27)
- keyword (20) and keywords (63)
- name (56) and names (12)
- feature (16) and features (63)
- picture (21) and pictures (10)
- sample (28) and samples (19)
- setter (11) and setters (26)
- shader (23) and shaders (13)
- spreadsheet (25) and spreadsheets (35)
- tooltip (42) and tooltips (52)
- utility (19) and utilities (67)
- value (64) and values (19)
- wildcard (33) and wildcards (15)